Seems obvious, but let’s say we have 2 arrays and I want to push some objects inside if certain condition is true. Generally speaking, it would be better like this:
let arr1 = []; let arr2 = []; if(someCond){ for(let i=0;i<5;i++){ arr1.push(i) } } else{ for(let i=0;i<5;i++){ arr2.push(i) } }
or like this:
let arr1 = []; let arr2 = []; for(let i=0;i<5;i++){ if(cond) arr1.push(i) else arr2.push(i) }
I think the second option looks shorter, but maybe it’s worse in performance.
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Answer
The best is:
const arr1 = []; const arr2 = []; const cond = Math.random() > 0.5; const arr = cond ? arr1 : arr2; for(let i = 0; i < 5; ++i){ arr.push(i); } console.log('arr1', arr1); console.log('arr2', arr2);