Jquery，检查数组中的值是否存在[复制]

This question already has an answer here:

这个问题已经有了答案:

How do I check if an array includes an object in JavaScript? 40 answers
如何检查一个数组是否包含JavaScript中的对象?40的答案

I believe this question will be fairly easy for the ones who played around with java script / jquery.

我相信这个问题对于那些使用java脚本/ jquery的人来说是相当容易的。

var arr = new Array();

$.map(arr, function() {
 if (this.id == productID) {
   this.price = productPrice;
 }else {
  arr.push({id: productID, price: productPrice})
 }
}

I guess the code above explains what I want in really simple way. I would imagine this $.map would work like this but unfortunately I couldn't get results with this.

我想上面的代码解释了我想要的非常简单的方法。我可以想象这一美元。地图就像这样，但不幸的是我无法得到结果。

What is the most simple and elegant way to do this? Do I truly go through all array just to find if a key's value is there or not?

做这件事最简单、最优雅的方法是什么?我是否真的要遍历所有数组以查找键值是否存在?

Does Jquery has something like isset($array['key'])?

Jquery是否有isset($array['key'])?

EDIT

编辑

I tried to use inArray but it keeps adding object to array even if there is a match.

我尝试使用inArray，但它会不断添加对象，即使有匹配。

if ( $.inArray(productID, arr) > -1) {
   var number = $.inArray(productID, arr);
   orderInfo[number].price = parseFloat(productPrice);
}else {
   orderInfo.push({id:productID, price:parseFloat(productPrice)});
}

5 个解决方案

#1

If you want to do it using .map() or just want to know how it works you can do it like this:

如果你想用。map()或者只是想知道它是如何工作的你可以这样做:

var added=false;
$.map(arr, function(elementOfArray, indexInArray) {
 if (elementOfArray.id == productID) {
   elementOfArray.price = productPrice;
   added = true;
 }
}
if (!added) {
  arr.push({id: productID, price: productPrice})
}

The function handles each element separately. The .inArray() proposed in other answers is probably the more efficient way to do it.

函数分别处理每个元素。在其他答案中提出的. inarray()可能是更有效的方法。

#2

209

http://api.jquery.com/jQuery.inArray/

if ($.inArray('example', myArray) != -1)
{
  // found it
}

#3

jQuery has the inArray function:

jQuery有inArray函数:

http://api.jquery.com/jQuery.inArray/

#4

    if ($.inArray('yourElement', yourArray) > -1)
    {
        //yourElement in yourArray
        //code here

    }

Reference: Jquery Array

参考:Jquery的数组

The $.inArray() method is similar to JavaScript's native .indexOf() method in that it returns -1 when it doesn't find a match. If the first element within the array matches value, $.inArray() returns 0.

$. inarray()方法类似于JavaScript的native . indexof()方法，当它没有找到匹配时，它返回-1。如果数组中的第一个元素匹配值，$. inarray()返回0。

#5

Try jQuery.inArray()

尝试jQuery.inArray()

Here is a jsfiddle link using the same code : http://jsfiddle.net/yrshaikh/SUKn2/

这里有一个使用相同代码的jsfiddle链接:http://jsfiddle.net/yrshaikh/SUKn2/。

$. inarray()方法类似于JavaScript的native . indexof()方法，当它没有找到匹配时，它返回-1。如果数组中的第一个元素匹配值，$.inArray()返回0。

Example Code :

示例代码:

<html>
   <head>
      <style>
         div { color:blue; }
         span { color:red; }
  </style>
      <script src="http://code.jquery.com/jquery-latest.js"></script>
   </head>
   <body>    
      <div>"John" found at <span></span></div>
      <div>4 found at <span></span></div>
      <div>"Karl" not found, so <span></span></div>
      <div>
         "Pete" is in the array, but not at or after index 2, so <span></span>
      </div>
      <script>
         var arr = [ 4, "Pete", 8, "John" ];
         var $spans = $("span");
         $spans.eq(0).text(jQuery.inArray("John", arr));
         $spans.eq(1).text(jQuery.inArray(4, arr));
         $spans.eq(2).text(jQuery.inArray("Karl", arr));
         $spans.eq(3).text(jQuery.inArray("Pete", arr, 2));
      </script>  
   </body>
</html>

Output:

输出:

"John" found at 3
4 found at 0
"Karl" not found, so -1
"Pete" is in the array, but not at or after index 2, so -1

#1

If you want to do it using .map() or just want to know how it works you can do it like this:

如果你想用。map()或者只是想知道它是如何工作的你可以这样做:

var added=false;
$.map(arr, function(elementOfArray, indexInArray) {
 if (elementOfArray.id == productID) {
   elementOfArray.price = productPrice;
   added = true;
 }
}
if (!added) {
  arr.push({id: productID, price: productPrice})
}

The function handles each element separately. The .inArray() proposed in other answers is probably the more efficient way to do it.

函数分别处理每个元素。在其他答案中提出的. inarray()可能是更有效的方法。

#2

209

http://api.jquery.com/jQuery.inArray/

if ($.inArray('example', myArray) != -1)
{
  // found it
}

#3

jQuery has the inArray function:

jQuery有inArray函数:

http://api.jquery.com/jQuery.inArray/

#4

    if ($.inArray('yourElement', yourArray) > -1)
    {
        //yourElement in yourArray
        //code here

    }

Reference: Jquery Array

参考:Jquery的数组

$. inarray()方法类似于JavaScript的native . indexof()方法，当它没有找到匹配时，它返回-1。如果数组中的第一个元素匹配值，$. inarray()返回0。

#5

Try jQuery.inArray()

尝试jQuery.inArray()

Here is a jsfiddle link using the same code : http://jsfiddle.net/yrshaikh/SUKn2/

这里有一个使用相同代码的jsfiddle链接:http://jsfiddle.net/yrshaikh/SUKn2/。

$. inarray()方法类似于JavaScript的native . indexof()方法，当它没有找到匹配时，它返回-1。如果数组中的第一个元素匹配值，$.inArray()返回0。

Example Code :

示例代码:

<html>
   <head>
      <style>
         div { color:blue; }
         span { color:red; }
  </style>
      <script src="http://code.jquery.com/jquery-latest.js"></script>
   </head>
   <body>    
      <div>"John" found at <span></span></div>
      <div>4 found at <span></span></div>
      <div>"Karl" not found, so <span></span></div>
      <div>
         "Pete" is in the array, but not at or after index 2, so <span></span>
      </div>
      <script>
         var arr = [ 4, "Pete", 8, "John" ];
         var $spans = $("span");
         $spans.eq(0).text(jQuery.inArray("John", arr));
         $spans.eq(1).text(jQuery.inArray(4, arr));
         $spans.eq(2).text(jQuery.inArray("Karl", arr));
         $spans.eq(3).text(jQuery.inArray("Pete", arr, 2));
      </script>  
   </body>
</html>

Output:

输出:

"John" found at 3
4 found at 0
"Karl" not found, so -1
"Pete" is in the array, but not at or after index 2, so -1

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Jquery，检查数组中的值是否存在[复制]

5 个解决方案

#1

#2

#3

#4

#5

#1

#2

#3

#4

#5

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