javascript - Comparing two arrays in jquery

Question

Using this code...

var a = ['volvo','random data'];
var b = ['random data'];
var unique = $.grep(a, function(element) {
    return $.inArray(element, b) == -1;
});

var result = unique ;

alert(result); 

...I am able to find which element of Array "a" is not in Array "b".

Now I need to find:

• if an element of Array "a" is in Array "b"
• what is its index in Array "b"

For example "Random data" is in both arrays, so I need to return its position in Array b which is zero index.

Answer 1

Regarding your comment, here is a solution:

with jQuery:

$.each( a, function( key, value ) {
    var index = $.inArray( value, b );
    if( index != -1 ) {
        console.log( index );
    }
});

without jQuery:

a.forEach( function( value ) {
    if( b.indexOf( value ) != -1 ) {
       console.log( b.indexOf( value ) );
    }
});