blocks|key|563277|text|您可以将负索引传递给.slice()。这将指示距集合末尾的偏移量。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|563278|var+member+=+"my+name+is+Mate";

var+last2+=+member.slice(-2);

alert(last2);+//+"te"|code-block|syntax|javascript|563279|entityMap|0|LINK|mutability|MUTABLE|url|https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/slice^0|A|8|A|8|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>You can pass a negative index to <a href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/slice" rel="noreferrer"><code>.slice()</code></a>. That will indicate an offset from the end of the set.</p>
<pre><code>var member = &quot;my name is Mate&quot;;

var last2 = member.slice(-2);

alert(last2); // &quot;te&quot;
</code></pre>


blocks|key|563078|text|尝试一下，请注意，您不需要在substring中指定结束索引。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|563079|var+characters+=+member.substr(member.length+-2);|code-block|syntax|javascript|563080|entityMap^0|E|9|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

<p>Try this, note that you don't need to specify the end index in <code>substring</code>.</p>

<pre><code>var characters = member.substr(member.length -2);
</code></pre>


blocks|key|563368|text|以下示例使用具有负索引的slice()|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|563369|​|563370|var+str+=+'my+name+is+maanu.';
console.log(str.slice(-3));+++++//+returns+'nu.'+last+two
console.log(str.slice(3,+-7));+//+returns+'name+is'
console.log(str.slice(0,+-1));++//+returns+'my+name+is+maanu'|code-block|syntax|javascript|563371|563372|entityMap^0|C|7|0|0|0|0^^$0|@$1|2|3|4|5|6|7|P|8|@$9|Q|A|R|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|S|8|@]|D|@]|E|$]]|$1|H|3|I|5|J|7|T|8|@]|D|@]|E|$K|L]]|$1|M|3|G|5|6|7|U|8|@]|D|@]|E|$]]|$1|N|3|-4|5|6|7|V|8|@]|D|@]|E|$]]]|O|$]]

<p>The following example uses <code>slice()</code> with negative indexes</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 str = 'my name is maanu.';
console.log(str.slice(-3));     // returns 'nu.' last two
console.log(str.slice(3, -7)); // returns 'name is'
console.log(str.slice(0, -1));  // returns 'my name is maanu'</code></pre>
</div>
</div>
</p>


blocks|key|563021|text|你可以试试|type|unstyled|depth|inlineStyleRanges|entityRanges|data|563022|member.substr(member.length-2);|code-block|syntax|javascript|563023|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>You can try</p>

<pre><code>member.substr(member.length-2);
</code></pre>


blocks|key|563343|text|如果它是一个整数，你需要它的一部分....|type|unstyled|depth|inlineStyleRanges|entityRanges|data|563344|var+result+=+number.toString().slice(-2);|code-block|syntax|javascript|563345|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>If it's an integer you need a part of....</p>

<pre><code>var result = number.toString().slice(-2);
</code></pre>


blocks|key|347056|text|您应该使用子字符串，而不是jQuery来完成此操作。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|347057|尝试如下所示：|347058|member.substring(member.length+-+2,+member.length)|code-block|syntax|javascript|347059|W3Schools+(非官方，但偶尔会有帮助)：http://www.w3schools.com/jsref/jsref_substring.asp|offset|length|347060|根据评论者的请求添加MDN链接：https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/substring|347061|entityMap|0|LINK|mutability|MUTABLE|url|http://www.w3schools.com/jsref/jsref_substring.asp|1|https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/substring^0|0|0|0|O|1E|0|0|G|2D|1|0^^$0|@$1|2|3|4|5|6|7|Y|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|Z|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|10|8|@]|9|@]|A|$G|H]]|$1|I|3|J|5|6|7|11|8|@]|9|@$K|12|L|13|1|14]]|A|$]]|$1|M|3|N|5|6|7|15|8|@]|9|@$K|16|L|17|1|18]]|A|$]]|$1|O|3|-4|5|6|7|19|8|@]|9|@]|A|$]]]|P|$Q|$5|R|S|T|A|$U|V]]|W|$5|R|S|T|A|$U|X]]]]

<p>You should use substring, not jQuery, to do this.</p>

<p>Try something like this:</p>

<pre><code>member.substring(member.length - 2, member.length)
</code></pre>

<p>W3Schools (not official, but occasionally helpful):   <a href="http://www.w3schools.com/jsref/jsref_substring.asp" rel="nofollow">http://www.w3schools.com/jsref/jsref_substring.asp</a></p>

<p>Adding MDN link as requested by commenter: <a href="https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/substring" rel="nofollow">https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/String/substring</a></p>


blocks|key|347131|text|var+member+=+"my+name+is+maanu";|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|347132|var+answer=member.substring(0,member.length+-+2);|unstyled|offset|length|style|CODE|347133|alert(answer);|347134|entityMap^0|0|0|1D|0|0^^$0|@$1|2|3|4|5|6|7|O|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|P|8|@$G|Q|H|R|I|J]]|9|@]|A|$]]|$1|K|3|L|5|6|7|S|8|@]|9|@]|A|$B|C]]|$1|M|3|-4|5|F|7|T|8|@]|9|@]|A|$]]]|N|$]]

<pre><code>var member = "my name is maanu";
</code></pre>

<p><code>var answer=member.substring(0,member.length - 2);
</code></p>

<pre><code>alert(answer);
</code></pre>


blocks|key|563414|text|Slice可用于查找子字符串。当我们知道索引时，我们可以使用另一种解决方案，比如索引加法器。两者的执行时间大致相同。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|563415|​|563416|const+primitiveStringMember+=+"my+name+is+Mate";

const+objectStringMember+=+new+String("my+name+is+Mate");
console.log(typeof+primitiveStringMember);//string
console.log(typeof+objectStringMember);//object


/*+However+when+we+use+.+operator+to+string+primitive+type,+JS+will+wrap+up+the+string+with+object.+That's+why+we+can+use+the+methods+String+object+type+for+the+primitive+type+string.
*/

//Slice+method
const+t0+=+performance.now();
slicedString+=+primitiveStringMember.slice(-2);//te
const+t1+=+performance.now();
console.log(`Call+to+do+slice+took+${t1+-+t0}+milliseconds.`);


//index+vise+adder+method
const+t2+=+performance.now();
length+=+primitiveStringMember.length
neededString+=+primitiveStringMember[length-2]%2BprimitiveStringMember[length-1];//te
const+t3+=+performance.now();
console.log(`Call+to+do+index+adder+took+${t3+-+t2}+milliseconds.`);|code-block|syntax|javascript|563417|563418|entityMap^0|0|0|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|M|8|@]|9|@]|A|$]]|$1|D|3|E|5|F|7|N|8|@]|9|@]|A|$G|H]]|$1|I|3|C|5|6|7|O|8|@]|9|@]|A|$]]|$1|J|3|-4|5|6|7|P|8|@]|9|@]|A|$]]]|K|$]]

<p>Slice can be used to find the substring. When we know the indexes we can use an alternative solution like index wise adder. Both are taking roughly the same time for execution.</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>const primitiveStringMember = "my name is Mate";

const objectStringMember = new String("my name is Mate");
console.log(typeof primitiveStringMember);//string
console.log(typeof objectStringMember);//object


/* However when we use . operator to string primitive type, JS will wrap up the string with object. That's why we can use the methods String object type for the primitive type string.
*/

//Slice method
const t0 = performance.now();
slicedString = primitiveStringMember.slice(-2);//te
const t1 = performance.now();
console.log(`Call to do slice took ${t1 - t0} milliseconds.`);


//index vise adder method
const t2 = performance.now();
length = primitiveStringMember.length
neededString = primitiveStringMember[length-2]+primitiveStringMember[length-1];//te
const t3 = performance.now();
console.log(`Call to do index adder took ${t3 - t2} milliseconds.`);</code></pre>
</div>
</div>
</p>


<p>I need to select last two characters from the variable, whether it is digit or letters.</p>
<p>For example:</p>
<pre><code>var member = &quot;my name is Mate&quot;;
</code></pre>
<p>I would like to show last two letters from the string in the <code>member</code> variable.</p>


How to select last two characters of a string

jQuery

我需要从变量中选择最后两个字符，无论是数字还是字母。例如：var member = "my name is Mate";我想在member变量中显示字符串的最后两个字母。

问如何选择字符串的最后两个字符
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问如何选择字符串的最后两个字符
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