这段代码如何返回2 ^ 4的电源？

Question

`var result = 1;
for (var counter = 0; counter < 4; counter = counter + 1)
  result = result * 2;
console.log(result);
// → 16`

结果的新值来自哪里？

Answer 1

我认为这很简单

有一个

result = 1

在循环中它将是

result = result * 2; //result is 2
result = result * 2; //result is 4
result = result * 2; //result is 8
result = result * 2; //result is 16

与2^4相同。

Answer 2

首先遍历result = 1 * 2

第二次循环通过result = 2(result from first) * 2

第三次通过result = 4(result from second) * 2

和上次结果= 8(result from third) * 2

循环只会经历4次，这就是你获得2^4

的方式