嗨，为什么 while 循环不继续到 -infinity 并在 -1 上停止

Question

Why don't continue the while loop until -infinity?

 <script>
        var number=[100,3,250,99,70,1,70];
        document.getElementById("demo1").innerHTML=maxValue(number);
        function maxValue(arr){
        var len=arr.length;
        var min=Infinity;
        while(len--)
        {
          if(arr[len]<min){
            min=arr[len];
          }
        }
          return min;
        }
      </script>

Answer 1

It uses the condition of the while statement with the value of len and if it is zero, then the iteration stops, because this value is falsy .

The following decrementing changes len , but has no influece anymore of the condition, because of its postfix nature of the decrement operator -- .

 function maxValue(arr) { var len = arr.length; var min = Infinity; while (len--) { console.log('len', len); if (arr[len] < min) { min = arr[len]; } } return min; } var number = [100, 3, 250, 99, 70, 1, 70]; console.log(maxValue(number));