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Difference between two lists in Javascript


var a1 = ['a', 'b'];
var a2 = ['a', 'b', 'c', 'd'];

Intersection


 let intersection = arr1.filter(x => arr2.includes(x));

For [1,2,3] [2,3] it will yield [2,3]. On the other hand, for [1,2,3] [2,3,5] will return the same thing.

Difference


let difference = arr1.filter(x => !arr2.includes(x));

For [1,2,3] [2,3] it will yield [1]. On the other hand, for [1,2,3] [2,3,5] will return the same thing.

Example


Array.prototype.diff = function(a) {
    return this.filter(function(i) {return a.indexOf(i) < 0;});
};


const dif1 = [1,2,3,4,5,6].diff( [3,4,5] );  
console.log(dif1); // => [1, 2, 6]


const dif2 = ["test1", "test2","test3","test4","test5","test6"].diff(["test1","test2","test3","test4"]);  
console.log(dif2); // => ["test5", "test6"]

Output

[ 1, 2, 6]
[ "test5", "test6"]


Conclusion

In this page (written and validated by ) you learned about . What's Next? If you are interested in completing Javascript tutorial, we encourage you simply to start here: Javascript Tutorial.



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