I have to filter out certain elements from an array in javascript and thought of using underscore.js for this purpose. As I am new to it,some help is appreciated.Please refer the code below , I have to find A \ B and assign the result to C . Does underscore.js has any convinience method to do that ?

function testUnderScore(){
    alert("underscore test");
    var a = [84, 99, 91, 65, 87, 55, 72, 68, 95, 42];
    var b = [ 87, 55, 72,42 ,13];
    var c = [];

    alert(c);
}

I have to filter out certain elements from an array in javascript and thought of using underscore.js for this purpose. As I am new to it,some help is appreciated.Please refer the code below , I have to find A \ B and assign the result to C . Does underscore.js has any convinience method to do that ?

function testUnderScore(){
    alert("underscore test");
    var a = [84, 99, 91, 65, 87, 55, 72, 68, 95, 42];
    var b = [ 87, 55, 72,42 ,13];
    var c = [];

    alert(c);
}

• javascript
• underscore.js

• I just found it out , c= _.without(a, b); will yeild A-B , I will also check the below answers and accept them. – Tito Commented Apr 9, 2012 at 8:35
• 1 Note: You should better use the proper syntax A \ B in text. – Kijewski Commented Apr 9, 2012 at 8:43

3 Answers 3

By using difference method:

var c = _.difference(a, b);

http://documentcloud.github.com/underscore/#difference

I have to find A- B and assign the result to C . Does underscore.js has any convinience method to do that ?

Yes, you can use difference ^{[View Docs]} method:

var c = _.difference(a, b);

How about:

var a = [1, 2, 5, 6], b = [6], c;

c = a.filter(
    function (aItem) {
        return !(~b.indexOf(aItem));
    }
);

console.log(c);

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