Do JavaScript or jQuery have a function that returns the element of an array whose index equal to the position of a given value in another array? (I could write my own, but I don't want to reinvent the wheel.)

Something like:

function vlookup(theElement, array1, array2) {
    $.each(array1, function(index, element) {
        if (element === theElement)
            return array2[index];
    });
    return null;
}

But, um... in the standard library.

Do JavaScript or jQuery have a function that returns the element of an array whose index equal to the position of a given value in another array? (I could write my own, but I don't want to reinvent the wheel.)

Something like:

function vlookup(theElement, array1, array2) {
    $.each(array1, function(index, element) {
        if (element === theElement)
            return array2[index];
    });
    return null;
}

But, um... in the standard library.

• javascript
• jquery

• Your example doesn't look like the typical vlookup usage, but what's wrong with coding it yourself? – Brad Christie Commented Mar 2, 2011 at 20:04
• I dislike coding something I could code not. Since I'm such a sloppy idiot, I prefer using actually designed/tested standard libraries. – isekaijin Commented Mar 2, 2011 at 21:15

1 Answer 1

Something like this perhaps?

Array.prototype.vlookup = function(needle,index,exactmatch){
    index = index || 0;
    exactmatch = exactmatch || false;
    for (var i = 0; i < this.length; i++){
        var row = this[i];

        if ((exactmatch && row[0]===needle) || row[0].toLowerCase().indexOf(needle.toLowerCase()) !== -1)
            return (index < row.length ? row[index] : row);
    }
    return null;
}

Then you can use it against a double array, like so

Depending your purpose, you can modify the indexOf to make both strings lowercase first so the parison doesn't fail with "foo" vs "FOO". Note also that if index exceeds the row's length, the entire row is returned (this can be changed to the first element (or whatever) easily by modifying the : row); portion.