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Javascript 函数don';t从数组返回值_Javascript_Arrays_Typescript - Fatal编程技术网

Javascript 函数don';t从数组返回值

Javascript 函数don';t从数组返回值,javascript,arrays,typescript,Javascript,Arrays,Typescript,我有一些代码片段 for(var i=0; i < this.arr2.length; i++) { arr.push({ id: i.toString(), label: this.arr2[i], display: () => this.arr2[i] }) } 工作正常您应该使用let关键字来声明块scopelocal变量 for(let = 0; i < this.arr2.le

我有一些代码片段

 for(var i=0; i < this.arr2.length; i++) {
      arr.push({
          id: i.toString(),
          label: this.arr2[i],
          display: () => this.arr2[i]
      })
  }

工作正常

您应该使用
let
关键字来声明块
scope
local变量

for(let = 0; i < this.arr2.length; i++) {
  arr.push({
      id: i.toString(),
      label: this.arr2[i],
      display: () => this.arr2[i]
  })
}
简短示例:

arr2=[1,2,3,4,5];
arr=arr2.map(功能(项目i){
返回{id:i,label:item,display:()=>item};
});
console.log(arr[1].display())
for(let = 0; i < this.arr2.length; i++) {
  arr.push({
      id: i.toString(),
      label: this.arr2[i],
      display: () => this.arr2[i]
  })
}
arr=arr2.map(function(item,i){
   return {id:i,label:item,display:()=>item};
});