typescript - 变量 'minSum'在分配之前使用

Question

let arrSort: number[] = arr.sort(), minSum: number;
   arrSort.forEach((a, b) => {
     if(b > 0){
       minSum += minSum + a;
       console.log(b)
     }
   })
   console.log(minSum); // Variable 'minSum' is used before being assigned. 

minSum 定义在顶部，但 typescript 仍然抛出错误 未分配

Answer 1

您需要初始化minSum才能在那里累积总和。另外，您还可以通过执行 minSum += minSum + a;

来添加两次

let arrSort: number[] = arr.sort(), minSum: number = 0;
   arrSort.forEach((a, b) => {
     if(b > 0){
       minSum += a;
       console.log(b)
     }
   })
   console.log(minSum); // Variable 'minSum' is used before being assigned. 

你可以玩一下here