javascript 불변성(immutable) 유지하면서 배열 다루기

Inmutable Push

function immutablePush(arr, newEntry){ return [ ...arr, newEntry ] }

Inmutable Pop

function immutablePop(arr){ return arr.slice(0, -1) }

Inmutable Unshift

function immutableUnshift(arr, newEntry){ return [ newEntry, ...arr ] }

Sort

function immutableSort(arr, compareFunction) {
return [ ...arr ].sort(compareFunction)
}
// or...
function immutableSort(arr, compareFunction) {
return arr.slice().sort(compareFunction)
}

Reverse

function immutableSort(arr, compareFunction) {
return [ ...arr ].reverse()
}
// or...
function immutableSort(arr, compareFunction) {
return arr.slice().reverse()
}

Splice

// ES6
function immutableSplice(arr, start, deleteCount, ...items) {
return [ ...arr.slice(0, start), ...items, ...arr.slice(start + deleteCount) ]
}

Delete

function immutableDelete (arr, index) {
return arr.slice(0,index).concat(arr.slice(index+1))
}

 

reference

• www.ma-no.org/en/programming/javascript/javascript-arrays-immutable-functions