Question

我有这个for循环，我想在每个循环中增加年份，但是我只得到最后一年，它们都重复多次。

for (let i = 0; i < 2; i++) {
  this.data.year = new Date().getFullYear() + i;
  this.data.noSolar = averageBill * increaseRate;
  this.data.withSolar = (contractAmount * .004) + customerCharge;
  this.data.saving = (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12);
  this.data.check = SREC;
  this.data.total = (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12) + SREC;

  this.dataSource.push(this.data);
}

在这种情况下，2020年显示两次。我想要类似2019和2020的东西。就像变量被多次引用一样。

Answer 1

应该在每次迭代中创建一个新对象。每次都指向同一对象。

您可以这样做

for (let i = 0; i < 2; i++) {
  this.dataSource.push({
     year : new Date().getFullYear() + i,
     noSolar : averageBill * increaseRate,
     withSolar : (contractAmount * .004) + customerCharge,
     saving : (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12),
     check : SREC,
     total : (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12) + SREC,
  });
}

或喜欢

for (let i = 0; i < 2; i++) {
      this.data=new DataSourceObject();
      this.data.year = new Date().getFullYear() + i;
      this.data.noSolar = averageBill * increaseRate;
      this.data.withSolar = (contractAmount * .004) + customerCharge;
      this.data.saving = (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12);
      this.data.check = SREC;
      this.data.total = (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12) + SREC;

      this.dataSource.push(this.data);
    }

Answer 2

对象的引用被推入数组。而是克隆或创建副本，然后按

    const temp = {};
    for (let i = 0; i < 2; i++) {
      this.data.year = new Date().getFullYear() + i;
      this.data.noSolar = averageBill * increaseRate;
      this.data.withSolar = (contractAmount * .004) + customerCharge;
      this.data.saving = (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12);
      this.data.check = SREC;
      this.data.total = (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12) + SREC;
      // this.dataSource.push(...this.data)
      Object.assign(temp, this.data);
      this.dataSource.push(temp);
    };

Answer 3

您可以尝试以下操作：-

for (let i = 0; i < 2; i++) {
  this.data.year = new Date().getFullYear() + i;
  this.data.noSolar = averageBill * increaseRate;
  this.data.withSolar = (contractAmount * .004) + customerCharge;
  this.data.saving = (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12);
  this.data.check = SREC;
  this.data.total = (contractAmount * .004 + customerCharge) * 12 - (averageBill * 12) + SREC;

  this.dataSource.push(Object.assign({}, this.data));
}

Javascript我的数组推仅获得最后一个值

3 个答案: