我如何做数组来分配另一个数组并修剪？

Question

I have textarea and textare jsccode as the following :

var checkName = (document.getElementById("List").value);
var tempcheckNames = checkName.split('\n');

and assign array another array with trim.

for (var i = 0; i < tempcheckNames.length;i++){
    checkNames = tempcheckNames[i].trim().split('\n');
}

But checkNames is empty because assign with not array ?

So I want to trim from textarea value (I did textarea value split so my array is textarea value ('\\n')

Answer 1

Define checkNames as an array, use .push() to add items to checkNames array within for loop, remove call to .split() within for loop

for (var i = 0, checkNames = [] /* define `checkNames` as an array */
    ; i < tempcheckNames.length
    ; i++) {
    checkNames.push(tempcheckNames[i].trim()); 
    // .split('\n'); `.split()` not needed here
}

Answer 2

You can push the values to an array to get all the split values

 var btn = document.getElementById('btn-show'); btn.addEventListener('click', btnShow); function btnShow (e) { var checkName = (document.getElementById("list").value); var tempcheckNames = checkName.split('\\n'); var checkNames = []; for (var i = 0; i < tempcheckNames.length;i++){ checkNames.push(tempcheckNames[i].trim()); } alert(checkNames); } 

 <textarea id='list'> </textarea> <button id='btn-show'>Show</button> 

Functional approach using Array.map

 var btn = document.getElementById('btn-show'); btn.addEventListener('click', btnShow); function btnShow (e) { var checkName = (document.getElementById("list").value); const checkNames = checkName.split('\\n').map((name) => name.trim() ); alert(checkNames); } 

  <textarea id='list'> </textarea> <button id='btn-show'>Show</button> 

Answer 3

这样，时间更短

var checkName = document.getElementById("List").value.split("\n").map(element => element.trim());