jQuery.inArray()

jQuery

previous page next page

jQuery.inArray()

Categories: Utilities

jQuery.inArray( value, array [, fromIndex ] ) Returns: Number

Description: Search for a specified value within an array and return its index (or -1 if not found).

  • version added: 1.2jQuery.inArray( value, array [, fromIndex ] )

    • value
      Type: Anything
      The value to search for.
    • array
      Type: Array
      An array through which to search.
    • fromIndex
      Type: Number
      The index of the array at which to begin the search. The default is 0, which will search the whole array.

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.

Because JavaScript treats 0 as loosely equal to false (i.e. 0 == false, but 0 !== false), if we're checking for the presence of value within array, we need to check if it's not equal to (or greater than) -1.

Example:

Report the index of some elements in the array.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
 
                                  

                                    

                                      
                                        <!DOCTYPE html>
                                      
                                    

                                  

                                  

                                    

                                      
                                        <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>
 POWERED BYHERONOTE
previous page start next page