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I have an array like [a, b, c, d] and I want to split it into 2 arrays like [a, b] and [c, d] and then merge it to have final result like [[a, b],[c, d]]. Is it possible to do without for loop?

Donnie
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    Possible duplicate of [Split array into two arrays](https://stackoverflow.com/questions/9933662/split-array-into-two-arrays) – Mohammad Usman Jun 20 '19 at 09:26
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    Why you want to do without loop ? – Code Maniac Jun 20 '19 at 09:26
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    Possible duplicate of [Split array into chunks](https://stackoverflow.com/questions/8495687/split-array-into-chunks) – adiga Jun 20 '19 at 09:27
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    I guess it's not really possible without loops unless you statically assign indexes to access each. Just use loop for it. – Martin Lloyd Jose Jun 20 '19 at 09:29
  • You gave an example, but do you need code for a more general case? If yes, how would you exactly specify that general case? Alternatively, share the code with the loop(s) and then we will try to rewrite it without loops. – www.admiraalit.nl Jun 20 '19 at 09:32

5 Answers5

5

You can use slice and push method like this

var arr = ['a', 'b', 'c', 'd'];
let index = 2;
let result = [];
result.push(arr.slice(0, index));
result.push(arr.slice(index))
console.log(result);
Hien Nguyen
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yes without loop you can do this But you should know at what index you have to split the array.

var arr = ['a', 'b', 'c', 'd'];  
var indexToSplit = arr.indexOf('c');
var first = arr.slice(0, indexToSplit);
var second = arr.slice(indexToSplit + 1);
var final = [first, second]
    console.log(final);
anurag sharma
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let arr = [0, 1, 9, 10, 8];
    let arr2 = arr.slice(1,3);
    let resultArr = [];

    if(arr2[1] > 1){
    resultArr.push(99); 
    }
else{
    resultArr.push(100); 

}
    console.log(resultArr)
Arvind Yadav
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You might like something like this:


a = 8;
b = { some: 'say'};
c = 'life';
d = true;

let o = {
    'a': [a, b, c, d],
    'a1': [],
    'a2': []
}
nSwitchBefore = 2;

o.a.forEach(function(item, i) {
   i < nSwitchBefore ? this.a1.push(item) : this.a2.push(item) ;
}.bind(o));

console.log(o);

Within the function block there is room for extra handling your array items. Like filtering or special treatment of certain types, using all conditions you want.

Duck
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I found another solution for this issue, without writing loops Lodash Chunk does this logic

_.chunk(['a', 'b', 'c', 'd'], 2);
// => [['a', 'b'], ['c', 'd']]

https://lodash.com/docs/

Donnie
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