Javascript 我在 while 循环中有一个嵌套的 for 循环，但它没有按预期工作

Question

I can't figure out why my code is going infinitely.

 var stateArray = ["CO", "AK", "CA", "KY", "NM"];
    var selectedStates = [];
    var important = 6
    while (important < 9)  {
        let j = Math.floor(Math.random() * 4);
        for (let i = 0; i < selectedStates.length;i++){
            if (stateArray[j] == selectedStates[i]){
                break;
            } else {
                selectedStates.push(stateArray[j]);
                console.log(selectedStates);
                important++
            }
        }
    }

If you could help me that would be amazing.

Answer 1

This is what you want if you want 3 random states selected

 var stateArray = ["CO", "AK", "CA", "KY", "NM"]; var selectedStates = []; var important = 6 while (important < 9) { let j = Math.floor(Math.random() * 4); selectedStates.push(stateArray[j]); ++important; } console.log(selectedStates)

Or if you don't want duplicates then

 var stateArray = ["CO", "AK", "CA", "KY", "NM"];
  var selectedStates = [];
  var important = 6
  while (important < 9) {
    let j = Math.floor(Math.random() * 4);
    if (selectedStates.includes((stateArray[j]))) {
      continue;
    }
    selectedStates.push(stateArray[j]);
    ++important;
  }

  console.log(selectedStates)

Answer 2

What it seems is:

You're in the rounds of while loop.

you didn't push anything in the selectedStates array yet, so how this for loop statement can be true i < selectedStates.length when i is already assigned 0 , and length of selectedStates is 0 as well.

and this while loop statement important < 9 is always true because it's not getting increased from 6 .