Question

我尝试在angular2（typescript）中向数组添加元素。它既不会抛出任何错误，也不会将元素添加到数组中。

代码段：

 let _dataSets:number[] = new Array(this.paymentModes.length);

for (let i = 0; i < this.paymentModes.length; i++) {
    let paymentMode = this.paymentModes[i];
    _dataSets.push(paymentMode.paymentModeTotalSales);
  }
  console.log(_dataSets);

有什么不对吗？

* paymentModes是来自WS响应的数组。

Answer 1

使用数组映射，确保属性paymentMode.paymentModeTotalSales的类型为number，否则转换为;将默认值设置为0：

let dataSets:number[];
dataSets = this.paymentModes.map(paymentMode => Number(paymentMode.paymentModeTotalSales || 0));
console.log(dataSets);

Answer 2

我能看到的唯一原因是paymentModeTotalSales不是数字。例如，以下工作正常。您可以在警报中看到值10。您可以尝试运行此here

module Test { 

   class PaymentMode {
        public paymentModeTotalSales: number;           
        constructor (paymentModeTotalSales: number) {   
            this.paymentModeTotalSales = paymentModeTotalSales;
            }
    }    
    let _dataSets: PaymentMode[] = [];
    let _paymentModes: PaymentMode[] = [];
    _paymentModes.push(new PaymentMode(10));
    _paymentModes.push(new PaymentMode(12));
    for (let i = 0; i < _paymentModes.length; i++) {
    let paymentMode = _paymentModes[i];
    _dataSets.push(new PaymentMode(paymentMode.paymentModeTotalSales));
    }
    alert(_dataSets[0].paymentModeTotalSales);

}

typescript push on array不会向其添加元素

2 个答案: