使用 underscore.js 从两个 arrays 中查找 A - B

Question

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);
}

Answer 1

By using difference method:

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

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

Answer 2

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);

Answer 3

How about:

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

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

console.log(c);