blocks|key|1004784|text|另一种方法是使用String.prototype.replace方法，将"replacer“函数作为第二个参数：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1004785|String.prototype.format+=+function+()+{
++var+i+=+0,+args+=+arguments;
++return+this.replace(/{}/g,+function+()+{
++++return+typeof+args[i]+!=+'undefined'+?+args[i%2B%2B]+:+'';
++});
};

var+bar1+=+'foobar',
++++bar2+=+'jumped',
++++bar3+=+'dog';

'The+lazy+{}+{}+over+the+{}'.format(bar3,+bar2,+bar1);
//+"The+lazy+dog+jumped+over+the+foobar"|code-block|syntax|javascript|1004786|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/replace^0|8|O|8|O|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]]|D|@$9|V|A|W|1|X]]|E|$]]|$1|F|3|G|5|H|7|Y|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Z|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

<p>Another approach, using the <a href="https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/replace" rel="noreferrer"><code>String.prototype.replace</code></a> method, with a "replacer" function as second argument:</p>

<pre><code>String.prototype.format = function () {
  var i = 0, args = arguments;
  return this.replace(/{}/g, function () {
    return typeof args[i] != 'undefined' ? args[i++] : '';
  });
};

var bar1 = 'foobar',
    bar2 = 'jumped',
    bar3 = 'dog';

'The lazy {} {} over the {}'.format(bar3, bar2, bar1);
// "The lazy dog jumped over the foobar"
</code></pre>


blocks|key|791074|text|有一种方法，但不是完全使用格式。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|791075|​|791076|var+name+=+"John";
var+age+=+19;
var+message+=+`My+name+is+${name}+and+I+am+${age}+years+old`;
console.log(message);|code-block|syntax|javascript|791077|791078|jsfiddle+-+link|offset|length|791079|entityMap|0|LINK|mutability|MUTABLE|url|http://jsfiddle.net/fz7s8oko/^0|0|0|0|0|B|4|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|W|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|X|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|Y|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|Z|8|@]|9|@$L|10|M|11|1|12]]|A|$]]|$1|N|3|-4|5|6|7|13|8|@]|9|@]|A|$]]]|O|$P|$5|Q|R|S|A|$T|U]]]]

<p>There is a way, but not exactly using format.  </p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>var name = "John";
var age = 19;
var message = `My name is ${name} and I am ${age} years old`;
console.log(message);</code></pre>
</div>
</div>
</p>

<p>jsfiddle - <a href="http://jsfiddle.net/fz7s8oko/" rel="noreferrer">link</a></p>


blocks|key|1004856|text|在寻找相同问题的答案时，我只找到了这个：https://github.com/davidchambers/string-format，这是“受Python的str.format()启发的JavaScript字符串格式化”。它看起来和python的format()函数很像。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|1004857|entityMap|0|LINK|mutability|MUTABLE|url|https://github.com/davidchambers/string-format^0|26|C|3F|8|K|1A|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@$9|O|A|P|B|C]|$9|Q|A|R|B|C]]|D|@$9|S|A|T|1|U]]|E|$]]|$1|F|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|G|$H|$5|I|J|K|E|$L|M]]]]

<p>Looking for an answer for the same question, I just found this: <a href="https://github.com/davidchambers/string-format">https://github.com/davidchambers/string-format</a>, which is "JavaScript string formatting inspired by Python’s <code>str.format()</code>". It seem it's pretty much the same as python's <code>format()</code> function.</p>


blocks|key|790519|text|摘自YAHOOs库：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|790520|YAHOO.Tools.printf+=+function()+{+
++var+num+=+arguments.length;+
++var+oStr+=+arguments[0];+++
++for+(var+i+=+1;+i+<+num;+i%2B%2B)+{+
++++var+pattern+=+"\\{"+%2B+(i-1)+%2B+"\\}";+
++++var+re+=+new+RegExp(pattern,+"g");+
++++oStr+=+oStr.replace(re,+arguments[i]);+
++}+
++return+oStr;+
}+|code-block|syntax|javascript|790521|它的名称如下：|790522|bar1+=+'foobar'
bar2+=+'jumped'
bar3+=+'dog'

foo+=+YAHOO.Tools.printf('The+lazy+{0}+{1}+over+the+{2}',+bar3,+bar2,+bar1);+|790523|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|N|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|P|8|@]|9|@]|A|$E|F]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

<p>Taken from YAHOOs library:</p>

<pre><code>YAHOO.Tools.printf = function() { 
  var num = arguments.length; 
  var oStr = arguments[0];   
  for (var i = 1; i &lt; num; i++) { 
    var pattern = "\\{" + (i-1) + "\\}"; 
    var re = new RegExp(pattern, "g"); 
    oStr = oStr.replace(re, arguments[i]); 
  } 
  return oStr; 
} 
</code></pre>

<p>Call it like: </p>

<pre><code>bar1 = 'foobar'
bar2 = 'jumped'
bar3 = 'dog'

foo = YAHOO.Tools.printf('The lazy {0} {1} over the {2}', bar3, bar2, bar1); 
</code></pre>


blocks|key|1005353|text|您可以在JS中使用模板文字，|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1005354|const+bar1+=+'foobar'
const+bar2+=+'jumped'
const+bar3+=+'dog'
foo+=+`The+lazy+${bar3}+${bar2}+over+the+${bar1}`|code-block|syntax|javascript|1005355|我认为这是有帮助的。|1005356|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

<p>You can use template literals in JS,</p>

<pre><code>const bar1 = 'foobar'
const bar2 = 'jumped'
const bar3 = 'dog'
foo = `The lazy ${bar3} ${bar2} over the ${bar1}`
</code></pre>

<p>I think this was helpful.</p>


blocks|key|1005269|text|Usando+split：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1005270|​|1005271|String.prototype.format+=+function+(args)+{
++++var+text+=+this
++++for(var+attr+in+args){
++++++++text+=+text.split('${'+%2B+attr+%2B+'}').join(args[attr]);
++++}
++++return+text
};

json+=+{'who':'Gendry',+'what':'will+sit',+'where':'in+the+Iron+Throne'}
text+=+'GOT:+${who}+${what}+${where}';

console.log('context:+',json);
console.log('template:+',text);
console.log('formated:+',text.format(json));|code-block|syntax|javascript|1005272|1005273|Usando+Regex：|1005274|String.prototype.format+=+function+(args)+{
++++var+text+=+this
++++for(var+attr+in+args){
++++++++var+rgx+=+new+RegExp('\\${'+%2B+attr+%2B+'}','g');
++++++++text+=+text.replace(rgx,+args[attr]);
++++}
++++return+text
};

json+=+{'who':'Gendry',+'what':'will+sit',+'where':'in+the+Iron+Throne'}
text+=+'GOT:+${who}+${what}+${where}';

console.log('context:+',json);
console.log('template:+',text);
console.log('formated:+',text.format(json));|1005275|1005276|entityMap^0|0|0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|S|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|T|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|U|8|@]|9|@]|A|$]]|$1|L|3|M|5|F|7|V|8|@]|9|@]|A|$G|H]]|$1|N|3|C|5|6|7|W|8|@]|9|@]|A|$]]|$1|O|3|-4|5|6|7|X|8|@]|9|@]|A|$]]]|P|$]]

<p>Usando split:</p>
<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>String.prototype.format = function (args) {
    var text = this
    for(var attr in args){
        text = text.split('${' + attr + '}').join(args[attr]);
    }
    return text
};

json = {'who':'Gendry', 'what':'will sit', 'where':'in the Iron Throne'}
text = 'GOT: ${who} ${what} ${where}';

console.log('context: ',json);
console.log('template: ',text);
console.log('formated: ',text.format(json));</code></pre>
</div>
</div>
</p>
<p>Usando Regex:
<div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>String.prototype.format = function (args) {
    var text = this
    for(var attr in args){
        var rgx = new RegExp('\\${' + attr + '}','g');
        text = text.replace(rgx, args[attr]);
    }
    return text
};

json = {'who':'Gendry', 'what':'will sit', 'where':'in the Iron Throne'}
text = 'GOT: ${who} ${what} ${where}';

console.log('context: ',json);
console.log('template: ',text);
console.log('formated: ',text.format(json));</code></pre>
</div>
</div>
</p>


blocks|key|1004928|text|此代码允许您准确地指定要用哪些字符串替换哪些方括号。括号不需要与参数的顺序相同，并且可以有多个括号。format函数接受一个值数组作为其参数，每个键都是一个带括号的“变量”，该变量被其相应的值替换。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1004929|String.prototype.format+=+function+(arguments)+{
++++var+this_string+=+'';
++++for+(var+char_pos+=+0;+char_pos+<+this.length;+char_pos%2B%2B)+{
++++++++this_string+=+this_string+%2B+this[char_pos];
++++}

++++for+(var+key+in+arguments)+{
++++++++var+string_key+=+'{'+%2B+key+%2B+'}'
++++++++this_string+=+this_string.replace(new+RegExp(string_key,+'g'),+arguments[key]);
++++}
++++return+this_string;
};

'The+time+is+{time}+and+today+is+{day},+{day},+{day}.+Oh,+and+did+I+mention+that+the+time+is+{time}.'.format({day:'Monday',time:'2:13'});
//'The+time+is+2:13+and+today+is+Monday,+Monday,+Monday.+Oh,+and+did+I+mention+that+the+time+is+2:13.'|code-block|syntax|javascript|1004930|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>This code allows you to specify exactly which brackets to replace with which strings. The brackets don't need to be in the same order as the arguments, and multiple brackets are possible. The format function takes an array of values as its parameter, with each key being one of the bracketed 'variables' which is replaced by its corresponding value.</p>

<pre><code>String.prototype.format = function (arguments) {
    var this_string = '';
    for (var char_pos = 0; char_pos &lt; this.length; char_pos++) {
        this_string = this_string + this[char_pos];
    }

    for (var key in arguments) {
        var string_key = '{' + key + '}'
        this_string = this_string.replace(new RegExp(string_key, 'g'), arguments[key]);
    }
    return this_string;
};

'The time is {time} and today is {day}, {day}, {day}. Oh, and did I mention that the time is {time}.'.format({day:'Monday',time:'2:13'});
//'The time is 2:13 and today is Monday, Monday, Monday. Oh, and did I mention that the time is 2:13.'
</code></pre>


blocks|key|1005293|text|String.prototype.format+=+function+()+{
++++var+i=0,args=arguments,formats={
++++++++"f":(v,s,c,f)=>{s=s%7C%7C'+',c=parseInt(c%7C%7C'0'),f=parseInt(f%7C%7C'-1');v=f>0?Math.floor(v).toString()%2B"."%2BMath.ceil(v*Math.pow(10,f)).toString().slice(-f):(f==-1?v.toString():Math.floor(v).toString());return+c>v.length?s.repeat(c-v.length)%2Bv:v;},
++++++++"d":(v,s,c,f)=>{s=s%7C%7C'+',c=parseInt(c%7C%7C'0');v=Math.floor(v).toString();return+c>v.length?s.repeat(c-v.length)%2Bv:v;},
++++++++"s":(v,s,c,f)=>{s=s%7C%7C'+',c=parseInt(c%7C%7C'0');return+c>v.length?s.repeat(c-v.length)%2Bv:v;},
++++++++"x":(v,s,c,f)=>{s=s%7C%7C'+',c=parseInt(c%7C%7C'0');v=Math.floor(v).toString(16);return+c>v.length?s.repeat(c-v.length)%2Bv:v;},
++++++++"X":(v,s,c,f)=>{s=s%7C%7C'+',c=parseInt(c%7C%7C'0');v=Math.floor(v).toString(16).toUpperCase();return+c>v.length?s.repeat(c-v.length)%2Bv:v;},
++++};
++++return+this.replace(/{(\d%2B)?:?([0=-_*])?(\d%2B)?\.?(\d%2B)?([dfsxX])}/g,+function+()+{
++++++++let+pos+=+arguments[1]%7C%7Ci;i%2B%2B;
++++++++return+typeof+args[pos]+!=+'undefined'+?+formats[arguments[5]](args[pos],arguments[2],arguments[3],arguments[4])+:+'';
++++});
};|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|1005294|unstyled|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|G|8|@]|9|@]|A|$B|C]]|$1|D|3|-4|5|E|7|H|8|@]|9|@]|A|$]]]|F|$]]

<pre><code>String.prototype.format = function () {
    var i=0,args=arguments,formats={
        "f":(v,s,c,f)=&gt;{s=s||' ',c=parseInt(c||'0'),f=parseInt(f||'-1');v=f&gt;0?Math.floor(v).toString()+"."+Math.ceil(v*Math.pow(10,f)).toString().slice(-f):(f==-1?v.toString():Math.floor(v).toString());return c&gt;v.length?s.repeat(c-v.length)+v:v;},
        "d":(v,s,c,f)=&gt;{s=s||' ',c=parseInt(c||'0');v=Math.floor(v).toString();return c&gt;v.length?s.repeat(c-v.length)+v:v;},
        "s":(v,s,c,f)=&gt;{s=s||' ',c=parseInt(c||'0');return c&gt;v.length?s.repeat(c-v.length)+v:v;},
        "x":(v,s,c,f)=&gt;{s=s||' ',c=parseInt(c||'0');v=Math.floor(v).toString(16);return c&gt;v.length?s.repeat(c-v.length)+v:v;},
        "X":(v,s,c,f)=&gt;{s=s||' ',c=parseInt(c||'0');v=Math.floor(v).toString(16).toUpperCase();return c&gt;v.length?s.repeat(c-v.length)+v:v;},
    };
    return this.replace(/{(\d+)?:?([0=-_*])?(\d+)?\.?(\d+)?([dfsxX])}/g, function () {
        let pos = arguments[1]||i;i++;
        return typeof args[pos] != 'undefined' ? formats[arguments[5]](args[pos],arguments[2],arguments[3],arguments[4]) : '';
    });
};
</code></pre>


blocks|key|1004703|text|JavaScript没有这样的函数AFAIK。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1004704|您可以通过修改String类的原型对象来创建一个，以添加一个format()方法，该方法接受可变数量的参数。|1004705|在format方法中，您必须获取字符串的实例值(实际字符串)，然后将其解析为'{}‘并插入适当的参数。|1004706|然后将新字符串返回给调用者。|1004707|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|K|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|L|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|M|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|I|$]]

<p>JavaScript doesn't have such a function AFAIK.</p>

<p>You could create one by modifying the String class's prototype object to add a format() method which takes a variable number of arguments.</p>

<p>In the format method you'd have to get the String's instance value (the actual string) and then parse it for '{}' and insert the appropriate argument.</p>

<p>Then return the new string to the caller.</p>


blocks|key|790747|text|尽管您可以创建自己的功能或使用其他人创建的功能(如sprintf)，但默认情况下，JavaScript没有字符串格式化功能。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|790748|entityMap|0|LINK|mutability|MUTABLE|url|http://www.diveintojavascript.com/projects/javascript-sprintf^0|P|7|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

<p>JavaScript does not have a string formatting function by default, although you can create your own or use one someone else has made (such as <a href="http://www.diveintojavascript.com/projects/javascript-sprintf" rel="nofollow">sprintf</a>)</p>


blocks|key|1005003|text|在文件中|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1005004|https://github.com/BruceSherwood/glowscript/blob/master/lib/glow/api_misc.js|offset|length|1005005|是一个函数String.prototype.format+=+function(args)，它完全实现了Python+string.format()函数，而不仅仅限于处理字符串。|1005006|entityMap|0|LINK|mutability|MUTABLE|url^0|0|0|24|0|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|P|8|@]|9|@$D|Q|E|R|1|S]]|A|$]]|$1|F|3|G|5|6|7|T|8|@]|9|@]|A|$]]|$1|H|3|-4|5|6|7|U|8|@]|9|@]|A|$]]]|I|$J|$5|K|L|M|A|$N|C]]]]

<p>In the file</p>

<p><a href="https://github.com/BruceSherwood/glowscript/blob/master/lib/glow/api_misc.js" rel="nofollow">https://github.com/BruceSherwood/glowscript/blob/master/lib/glow/api_misc.js</a></p>

<p>is a function String.prototype.format = function(args) that fully implements the Python string.format() function, not limited simply to handling character strings.</p>


blocks|key|1005175|text|对于那些正在寻找简单的ES6解决方案的人。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1005176|首先，我提供了一个函数，而不是扩展原生字符串原型，因为它通常是不受欢迎的。|1005177|​|1005178|//+format+function+using+replace()+and+recursion

const+format+=+(str,+arr)+=>+arr.length+>+1+
	?+format(str.replace('{}',+arr[0]),+arr.slice(1))+
	:+(arr[0]+&&+str.replace('{}',+arr[0]))+%7C%7C+str

//+Example+usage

const+str1+=+'The+{}+brown+{}+jumps+over+the+{}+dog'

const+formattedString+=+formatFn(str1,+['quick','fox','lazy'])

console.log(formattedString)|code-block|syntax|javascript|1005179|1005180|entityMap^0|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|N|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|P|8|@]|9|@]|A|$]]|$1|F|3|G|5|H|7|Q|8|@]|9|@]|A|$I|J]]|$1|K|3|E|5|6|7|R|8|@]|9|@]|A|$]]|$1|L|3|-4|5|6|7|S|8|@]|9|@]|A|$]]]|M|$]]

<p>For those looking for a simple ES6 solution. </p>

<p>First of all I'm providing a function instead of extending native String prototype because it is generally discouraged.</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>// format function using replace() and recursion

const format = (str, arr) =&gt; arr.length &gt; 1 
	? format(str.replace('{}', arr[0]), arr.slice(1)) 
	: (arr[0] &amp;&amp; str.replace('{}', arr[0])) || str

// Example usage

const str1 = 'The {} brown {} jumps over the {} dog'

const formattedString = formatFn(str1, ['quick','fox','lazy'])

console.log(formattedString)</code></pre>
</div>
</div>
</p>


blocks|key|791377|text|如果您(像我一样)只需要python的格式函数的有限子集来进行简单的字符串替换，并且性能并不重要，那么一个非常简单的29行纯Javascript函数就足够了。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|791378|Javascript调用：format(str,+data)|offset|length|style|CODE|791379|类似的python调用：str.format(**data)，但需要注意的是，如果字符串包含的变量名在所提供的数据中找不到，则此javascript函数不会抛出错误。|791380|/*
+*+format(str,+data):+analogous+to+Python's+str.format(**data)
+*
+*+Example:
+*+++let+data+=+{
+*+++++user:+{
+*+++++++name:+{+first:+'Jane',+last:+'Doe'+}
+*+++++},
+*+++++email:+'jane@doe.com',
+*+++++groups:+["one","two"]
+*+++};
+*
+*+++let+str+=+'Hi+{user.name.first}+{user.name.last},+your+email+address+is+{email},+and+your+second+group+is+{groups[1]}'
+*+
+*+++format(str,+data)
+*+++=>+returns+"Hi+Jane+Doe,+your+email+address+is+jane@doe.com,+and+your+second+group+is+two"
+*/

function+format(str,+data)+{
++++var+varnames+=+{};
++++function+array_path(path,+i)+{
++++++++var+this_k+=+'['+%2B+i+%2B+']';
++++++++if+(!path.length)
++++++++++++return+[this_k];
++++++++path+=+path.slice();
++++++++path[path.length+-+1]+%2B=+this_k;
++++++++return+path;
++++}
++++function+add_varnames(this_data,+path)+{
++++++++if+(this_data.constructor+==+Array)+{
++++++++++++for+(var+i+=+0;+i+<+this_data.length;+i%2B%2B)
++++++++++++++++add_varnames(this_data[i],+array_path(path,+i));
++++++++}
++++++++else+if+(this_data.constructor+==+Object)+{
++++++++++++for+(var+k+in+this_data)
++++++++++++++++add_varnames(this_data[k],+path.concat(k));
++++++++}
++++++++else+{
++++++++++++var+varname+=+'{'+%2B+path.join('.')+%2B+'}';
++++++++++++varnames[varname]+=+String(this_data);
++++++++}
++++}
++++add_varnames(data,+[]);
++++for+(var+varname+in+varnames)
++++++++str+=+str.replace(varname,+varnames[varname]);
++++return+str;
}|code-block|syntax|javascript|791381|entityMap^0|0|D|H|0|C|I|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|R|8|@$D|S|E|T|F|G]]|9|@]|A|$]]|$1|H|3|I|5|6|7|U|8|@$D|V|E|W|F|G]]|9|@]|A|$]]|$1|J|3|K|5|L|7|X|8|@]|9|@]|A|$M|N]]|$1|O|3|-4|5|6|7|Y|8|@]|9|@]|A|$]]]|P|$]]

<p>If you (like me) only need the limited subset of python's format function for simple string replacement, and performance is not critical, a very simple 29-line pure-Javascript function may suffice. </p>

<p>Javascript call: <code>format(str, data)</code></p>

<p>Analogous python call: <code>str.format(**data)</code>, with the caveat that this javascript function, unlike Python's, does not throw an error if the string contains a varname that is not found in the provided data.</p>

<pre><code>/*
 * format(str, data): analogous to Python's str.format(**data)
 *
 * Example:
 *   let data = {
 *     user: {
 *       name: { first: 'Jane', last: 'Doe' }
 *     },
 *     email: 'jane@doe.com',
 *     groups: ["one","two"]
 *   };
 *
 *   let str = 'Hi {user.name.first} {user.name.last}, your email address is {email}, and your second group is {groups[1]}'
 * 
 *   format(str, data)
 *   =&gt; returns "Hi Jane Doe, your email address is jane@doe.com, and your second group is two"
 */

function format(str, data) {
    var varnames = {};
    function array_path(path, i) {
        var this_k = '[' + i + ']';
        if (!path.length)
            return [this_k];
        path = path.slice();
        path[path.length - 1] += this_k;
        return path;
    }
    function add_varnames(this_data, path) {
        if (this_data.constructor == Array) {
            for (var i = 0; i &lt; this_data.length; i++)
                add_varnames(this_data[i], array_path(path, i));
        }
        else if (this_data.constructor == Object) {
            for (var k in this_data)
                add_varnames(this_data[k], path.concat(k));
        }
        else {
            var varname = '{' + path.join('.') + '}';
            varnames[varname] = String(this_data);
        }
    }
    add_varnames(data, []);
    for (var varname in varnames)
        str = str.replace(varname, varnames[varname]);
    return str;
}
</code></pre>


blocks|key|791462|text|据PatrikAkerstrand报道，我自己的精简版YAHOO's+printf：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|791463|​|791464|function+format()+{+
++return+[...arguments].reduce((acc,+arg,+idx)+=>+
++++acc.replace(new+RegExp("\\{"+%2B+(idx+-+1)+%2B+"\\}",+"g"),+arg));
}

console.log(
++format('Confirm+{1}+want+{0}+beers',+3,+'you')
);|code-block|syntax|javascript|791465|791466|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/a/4974284/309917^0|Z|6|R|E|0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|V|8|@$9|W|A|X|B|C]]|D|@$9|Y|A|Z|1|10]]|E|$]]|$1|F|3|G|5|6|7|11|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|12|8|@]|D|@]|E|$K|L]]|$1|M|3|G|5|6|7|13|8|@]|D|@]|E|$]]|$1|N|3|-4|5|6|7|14|8|@]|D|@]|E|$]]]|O|$P|$5|Q|R|S|E|$T|U]]]]

<p>My own srtipped down version of <a href="https://stackoverflow.com/a/4974284/309917">YAHOO's <code>printf</code></a> reported by PatrikAkerstrand:</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-js lang-js prettyprint-override"><code>function format() { 
  return [...arguments].reduce((acc, arg, idx) =&gt; 
    acc.replace(new RegExp("\\{" + (idx - 1) + "\\}", "g"), arg));
}

console.log(
  format('Confirm {1} want {0} beers', 3, 'you')
);</code></pre>
</div>
</div>
</p>


blocks|key|1005522|text|无需使用额外函数即可简单实现|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1005523|[bar1,+bar2,+bar3].reduce(
++(str,+val)+=>+str.replace(/{}/,+val),
++'The+lazy+{}+{}+over+the+{}'
)|code-block|syntax|javascript|1005524|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

<p>Simple implementation without using extra function</p>
<pre><code>[bar1, bar2, bar3].reduce(
  (str, val) =&gt; str.replace(/{}/, val),
  'The lazy {} {} over the {}'
)
</code></pre>


<p>Python has this beautiful function to turn this:</p>

<pre><code>bar1 = 'foobar'
bar2 = 'jumped'
bar3 = 'dog'

foo = 'The lazy ' + bar3 + ' ' + bar2 ' over the ' + bar1
# The lazy dog jumped over the foobar
</code></pre>

<p>Into this:</p>

<pre><code>bar1 = 'foobar'
bar2 = 'jumped'
bar3 = 'dog'

foo = 'The lazy {} {} over the {}'.format(bar3, bar2, bar1)
# The lazy dog jumped over the foobar
</code></pre>

<p>Does JavaScript have such a function? If not, how would I create one which follows the same syntax as Python's implementation?</p>


JavaScript equivalent of Python's format() function?

Python有一个漂亮的函数来实现这一点：bar1 = 'foobar'bar2 = 'jumped'bar3 = 'dog'foo = 'The lazy ' + bar3 + ' ' + bar2 ' over the ' + bar1# The lazy dog jumped over the foobar如下所示：bar1 = 'foobar'bar2 = 'jumped'bar3 = '

问Python的JavaScript ()函数的等价物？
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