How to Slice array Elements that is already present in another array in JavaScript/Jquery

Question

I have 2 arrays of time string. i want to remove elements of arr1 that is already presented in arr2.

These are my arry :

 arr1 = ["05:30", "05:45", "06:00", "06:15", "06:30", "06:45", "07:00", "07:15", "07:30", "07:45", "08:00", "08:15", "08:30", "08:45", "09:00", "09:15", "09:30", "09:45", "10:00", "10:15", "10:30", "10:45", "11:00", "11:15", "11:30", "11:45", "12:00", "12:15", "12:30", "12:45", "13:00", "13:15", "13:30", "13:45", "14:00", "14:15", "14:30", "14:45", "15:00", "15:15", "15:30", "15:45", "16:00", "16:15", "16:30", "16:45", "17:00", "17:15", "17:30", "17:45", "18:00", "18:15", "18:30", "18:45", "19:00", "19:15", "19:30", "19:45", "20:00", "20:15", "20:30", "20:45", "21:00", "21:15", "21:30", "21:45", "22:00", "22:15", "22:30", "22:45", "23:00", "23:15", "23:30"]

    arr2=["05:30", "05:45", "06:00", "06:15", "06:30", "06:45", "07:00", "07:15", "07:30", "07:45", "08:00", "13:00", "22:00", "22:15"]

Please help . Thanks in Advance

Data Is Currently Sorted but that is not required or important for me. — Sourav Mukherjee, Jun 24 '16 at 11:54
This is nothing but union of two arrays...see http://stackoverflow.com/questions/3629817/getting-a-union-of-two-arrays-in-javascript — Nitin Dhomse, Jun 24 '16 at 11:56
Can not answer because it's already an duplicate, but you can go with `grep` and `inArray`. https://jsfiddle.net/wvmpha59/ — eisbehr, Jun 24 '16 at 11:59

score 1 · Answer 1 · answered Jun 24 '16 at 11:54

1

You can create hash map on arr2 first

var lookupMap = {};

arr2.forEach(function(value){
lookupMap[value] = true;
});

arr1 = arr1.filter(function(value) {
return !lookupMap[value]
});

answered Jun 24 '16 at 11:54

Piyush.kapoor

6,041
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1

Thanks For helping ;) – Sourav Mukherjee Jun 24 '16 at 12:01

Nina Scholz · Accepted Answer · 2016-06-24T12:04:14.507

You could filter it with a hash table, made from the second array.

var arr1 = ["05:30", "05:45", "06:00", "06:15", "06:30", "06:45", "07:00", "07:15", "07:30", "07:45", "08:00", "08:15", "08:30", "08:45", "09:00", "09:15", "09:30", "09:45", "10:00", "10:15", "10:30", "10:45", "11:00", "11:15", "11:30", "11:45", "12:00", "12:15", "12:30", "12:45", "13:00", "13:15", "13:30", "13:45", "14:00", "14:15", "14:30", "14:45", "15:00", "15:15", "15:30", "15:45", "16:00", "16:15", "16:30", "16:45", "17:00", "17:15", "17:30", "17:45", "18:00", "18:15", "18:30", "18:45", "19:00", "19:15", "19:30", "19:45", "20:00", "20:15", "20:30", "20:45", "21:00", "21:15", "21:30", "21:45", "22:00", "22:15", "22:30", "22:45", "23:00", "23:15", "23:30"],
    arr2 = ["05:30", "05:45", "06:00", "06:15", "06:30", "06:45", "07:00", "07:15", "07:30", "07:45", "08:00", "13:00", "22:00", "22:15"],
    hash = {};

arr2.forEach(function (a) {
    hash[a] = true;
});

arr1 = arr1.filter(function (a) {
    return !hash[a];
});

console.log(arr1);

Proposal for sorted data.

var arr1 = ["05:30", "05:45", "06:00", "06:15", "06:30", "06:45", "07:00", "07:15", "07:30", "07:45", "08:00", "08:15", "08:30", "08:45", "09:00", "09:15", "09:30", "09:45", "10:00", "10:15", "10:30", "10:45", "11:00", "11:15", "11:30", "11:45", "12:00", "12:15", "12:30", "12:45", "13:00", "13:15", "13:30", "13:45", "14:00", "14:15", "14:30", "14:45", "15:00", "15:15", "15:30", "15:45", "16:00", "16:15", "16:30", "16:45", "17:00", "17:15", "17:30", "17:45", "18:00", "18:15", "18:30", "18:45", "19:00", "19:15", "19:30", "19:45", "20:00", "20:15", "20:30", "20:45", "21:00", "21:15", "21:30", "21:45", "22:00", "22:15", "22:30", "22:45", "23:00", "23:15", "23:30"],
    arr2 = ["05:30", "05:45", "06:00", "06:15", "06:30", "06:45", "07:00", "07:15", "07:30", "07:45", "08:00", "13:00", "22:00", "22:15"],
    j = 0;

arr1 = arr1.filter(function (a) {
    while (arr2[j] < a) {
        j++;
    }
    return arr2[j] !== a;
});

console.log(arr1);

Thanks for the answer & example with snippet :) – Sourav Mukherjee Jun 24 '16 at 12:00 — Sourav Mukherjee, Jun 24 '16 at 12:00

How to Slice array Elements that is already present in another array in JavaScript/Jquery

2 Answers2