blocks|key|203462|text|将[]与字符串一起使用可以动态地从对象中提取属性。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|203463|var+a+=+{+foo:+123+};
a.foo++++//+123
a['foo']+//+123

var+str+=+'foo';
a[str]+++//+123|code-block|syntax|javascript|203464|这意味着我们可以像这样重构你的方法，只需传入你想以字符串形式读取的属性的名称即可。|203465|var+getKeyValueMap+=+function(data,+keyPropName,+valuePropName)+{
++return+$.map(data,+function(item,+i)+{
++++return+{
++++++key:+++item[keyPropName],
++++++value:+item[valuePropName]
++++}
++});
};

service.getData(function(data)+{
++return+getKeyValueMap(data,+'data1',+'data2');
});

service.getSomething(function(data)+{
++return+getKeyValueMap(data,+'something1',+'something2');
});|203466|entityMap^0|1|2|0|0|0|0^^$0|@$1|2|3|4|5|6|7|Q|8|@$9|R|A|S|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|T|8|@]|D|@]|E|$I|J]]|$1|K|3|L|5|6|7|U|8|@]|D|@]|E|$]]|$1|M|3|N|5|H|7|V|8|@]|D|@]|E|$I|J]]|$1|O|3|-4|5|6|7|W|8|@]|D|@]|E|$]]]|P|$]]

use <code>[]</code> with a string to pull out properties from objects dynamically.

<pre><code>var a = { foo: 123 };
a.foo // 123
a['foo'] // 123

var str = 'foo';
a[str] // 123
</code></pre>

Which means we can refactor your method like so, just pass in the names of the properties you want to read as strings.

<pre><code>var getKeyValueMap = function(data, keyPropName, valuePropName) {
 return $.map(data, function(item, i) {
 return {
 key: item[keyPropName],
 value: item[valuePropName]
 }
 });
};

service.getData(function(data) {
 return getKeyValueMap(data, 'data1', 'data2');
});

service.getSomething(function(data) {
 return getKeyValueMap(data, 'something1', 'something2');
});
</code></pre>

blocks|key|421721|text|试试这个：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|421722|service.getData(function(data,+props)+{//+props+is+a+property+object
++++var+map+=+{};
++++map+=+$.map(data,+function(item,+i)+{
++++++++var+entry+=+{};

++++++++for+(var+key+in+props)+{
++++++++++++entry[key]+=+item[key]
++++++++}

++++++++return+entry;
++++});
});|code-block|syntax|javascript|421723|或者使用属性数组|421724|service.getData(function(data,+props)+{//+props+is+like+['data1',+'data2']
++++var+map+=+{};
++++map+=+$.map(data,+function(item,+i)+{
++++++++var+entry+=+{};

++++++++for+(var+j+=+0,+k+=+props.length;+j+<+k;+j%2B%2B)+{
++++++++++++entry[props[j]]+=+item[props[j]]
++++++++}

++++++++return+entry;
++++});
});|421725|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|$]]

try this:

<pre><code>service.getData(function(data, props) {// props is a property object
 var map = {};
 map = $.map(data, function(item, i) {
 var entry = {};

 for (var key in props) {
 entry[key] = item[key]
 }

 return entry;
 });
});
</code></pre>

or use a property array 

<pre><code>service.getData(function(data, props) {// props is like ['data1', 'data2']
 var map = {};
 map = $.map(data, function(item, i) {
 var entry = {};

 for (var j = 0, k = props.length; j &lt; k; j++) {
 entry[props[j]] = item[props[j]]
 }

 return entry;
 });
});
</code></pre>

blocks|key|203537|text|您需要传递item对象和item-keys到entry-keys的映射。这可以是两个数组、一个元组数组或其他东西，也可以是一个对象。我能想到的最简单的方法是将描述符对象更改为条目本身：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|203538|function+mapPropertyNames(source,+dest)+{
++++for+(var+prop+in+dest)
++++++++dest[prop]+=+source[dest[prop]];
++++return+dest;
}

//+and+use+it+like+this:

var+map+=+$.map(data,+function(item,+i)+{
++++return+mapPropertyNames(item,+{key:"something1",+value:"something2"});
});|code-block|syntax|javascript|203539|entityMap^0|5|4|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|$]]

You will need to pass the <code>item</code> object and a map of item-keys to entry-keys. This could either be two arrays, an array of tuples or something, or an object. Most simple method I could think of is to change the descriptor object into the entry itself:

<pre><code>function mapPropertyNames(source, dest) {
 for (var prop in dest)
 dest[prop] = source[dest[prop]];
 return dest;
}

// and use it like this:

var map = $.map(data, function(item, i) {
 return mapPropertyNames(item, {key:"something1", value:"something2"});
});
</code></pre>

blocks|key|203576|text|就像这样|type|unstyled|depth|inlineStyleRanges|entityRanges|data|203577|service.getData(function(data)+{
++++var+map+=+{};
++++var+varNamePrefix+=+'data';
++++map+=+$.map(data,+function(item,+i)+{
++++++++return+getProperties(item,+varNamePrefix);
++++});
});

service.getSomething(function(data)+{
++++var+map+=+{};
++++var+varNamePrefix+=+'something';
++++map+=+$.map(data,+function(item,+i)+{
++++++++return+getProperties(item,+varNamePrefix);
++++});
});

function+getProperties(item,+varNamePrefix)+{
++++var+ret+=+{};
++++ret.key+=+item[varNamePrefix+%2B+'1'];
++++ret.value+=+item[varNamePrefix+%2B+'2'];
++++return+ret;
}|code-block|syntax|javascript|203578|可能会有帮助？|203579|基本上，您可以使用一个接受属性前缀的函数，并使用它来形成要从项目中获取的实际属性名称。|203580|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]]|$1|G|3|H|5|6|7|O|8|@]|9|@]|A|$]]|$1|I|3|J|5|6|7|P|8|@]|9|@]|A|$]]|$1|K|3|-4|5|6|7|Q|8|@]|9|@]|A|$]]]|L|$]]

Something like 

<pre><code>service.getData(function(data) {
 var map = {};
 var varNamePrefix = 'data';
 map = $.map(data, function(item, i) {
 return getProperties(item, varNamePrefix);
 });
});

service.getSomething(function(data) {
 var map = {};
 var varNamePrefix = 'something';
 map = $.map(data, function(item, i) {
 return getProperties(item, varNamePrefix);
 });
});

function getProperties(item, varNamePrefix) {
 var ret = {};
 ret.key = item[varNamePrefix + '1'];
 ret.value = item[varNamePrefix + '2'];
 return ret;
}
</code></pre>

May help?

Basically, you could use a function that takes a property prefix and uses it to form the actual property names to get from items.

blocks|key|421815|text|这可以使用[]运算符来完成，而不是像in+this+fiddle+ive+created+just+for+you+:D一样使用.-notation|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|421816|++++var+data+=+[{
++++++++data1:+'foo',
++++++++data2:+'bar',
++++++++something1:+'sparky',
++++++++something2:+'arf+arf!'},
++++{
++++++++data1:+'My+name+is',
++++++++data2:+'What?',
++++++++something1:+'my+name+is',
++++++++something2:+'Who?!'}
++++];

++++function+test(data,+prop)+{
++++++++var+d_length+=+data.length;
++++++++for+(var+i+=+0;+i+<+d_length;+i%2B%2B)+{
++++++++++++alert(data[i][prop]);
++++++++}
++++}

++++test(data,+'data1');|code-block|syntax|javascript|421817|entityMap|0|LINK|mutability|MUTABLE|url|http://jsfiddle.net/5prnp/^0|5|2|1S|1|I|16|0|0|0^^$0|@$1|2|3|4|5|6|7|S|8|@$9|T|A|U|B|C]|$9|V|A|W|B|C]]|D|@$9|X|A|Y|1|Z]]|E|$]]|$1|F|3|G|5|H|7|10|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|11|8|@]|D|@]|E|$]]]|L|$M|$5|N|O|P|E|$Q|R]]]]

this can be done using the <code>[]</code> operators instead of the <code>.</code>-notation just like <a href="http://jsfiddle.net/5prnp/" rel="nofollow">in this fiddle ive created just for you :D</a>:

<pre><code> var data = [{
 data1: 'foo',
 data2: 'bar',
 something1: 'sparky',
 something2: 'arf arf!'},
 {
 data1: 'My name is',
 data2: 'What?',
 something1: 'my name is',
 something2: 'Who?!'}
 ];

 function test(data, prop) {
 var d_length = data.length;
 for (var i = 0; i &lt; d_length; i++) {
 alert(data[i][prop]);
 }
 }

 test(data, 'data1');
</code></pre>

I'm not sure if the title is appropriate for what I am trying to achieve

I am mapping JSON results to an array. Because I need to do this over and over again I would like to put the code into one function.

In the following examples I am repeating myself. I have properties called item.data1, item.data2 and in the second example item.something1, item.something2 ... How can I pass those properties as "general" arguments to the newly created function in order to use them there and not repeat myself to return those maps? The new function should be useable for the two examples below as well as for other cases where the properties could have different names.

<pre><code>service.getData(function(data) {
 var map = {};
 map = $.map(data, function(item, i) {
 var entry = {};

 entry.key = item.data1;
 entry.value = item.data2;

 return entry;
 });
});

service.getSomething(function(data) {
 var map = {};
 map = $.map(data, function(item, i) {
 var entry = {};

 entry.key = item.something1;
 entry.value = item.something2;

 return entry;
 });
});
</code></pre>

How to pass an object property as a parameter? (JavaScript)

JSON

我不确定这个标题是否适合我正在努力实现的目标我将JSON结果映射到一个数组。因为我需要一遍又一遍地做这件事，所以我想把代码放到一个函数中。在下面的例子中，我在重复我自己。我有名为item.data1、item.data2的属性，在第二个示例中有item.something1、item.something2……我如何将这...

问如何将对象属性作为参数传递？(JavaScript)
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