我有其他的解。

你可以使用round()来代替toFixed()

var twoPlacedFloat = parseFloat(yourString).round(2)

你可以使用toFixed()来做到这一点

var twoPlacedFloat = parseFloat(yourString).toFixed(2)

Solution for FormArray controllers 

初始化FormArray表单生成器

  formInitilize() {
    this.Form = this._formBuilder.group({
      formArray: this._formBuilder.array([this.createForm()])
    });
  }

创建表单

  createForm() {
    return (this.Form = this._formBuilder.group({
      convertodecimal: ['']
    }));
  }

将表单值设置为表单控制器

  setFormvalues() {
    this.Form.setControl('formArray', this._formBuilder.array([]));
    const control = <FormArray>this.resourceBalanceForm.controls['formArray'];
    this.ListArrayValues.forEach((x) => {
      control.push(this.buildForm(x));
    });
  }

  private buildForm(x): FormGroup {
    const bindvalues= this._formBuilder.group({
      convertodecimal: x.ArrayCollection1? parseFloat(x.ArrayCollection1[0].name).toFixed(2) : '' // Option for array collection
// convertodecimal: x.number.toFixed(2)    --- option for two decimal value 
    });

    return bindvalues;
  }

试试这个(参见代码中的注释):

function fixInteger(el) {
    // this is element's value selector, you should use your own
    value = $(el).val();
    if (value == '') {
        value = 0;
    }
    newValue = parseInt(value);
    // if new value is Nan (when input is a string with no integers in it)
    if (isNaN(newValue)) {
        value = 0;
        newValue = parseInt(value);
    }
    // apply new value to element
    $(el).val(newValue);
}

function fixPrice(el) {
    // this is element's value selector, you should use your own
    value = $(el).val();
    if (value == '') {
        value = 0;
    }
    newValue = parseFloat(value.replace(',', '.')).toFixed(2);
    // if new value is Nan (when input is a string with no integers in it)
    if (isNaN(newValue)) {
        value = 0;
        newValue = parseFloat(value).toFixed(2);
    }
    // apply new value to element
    $(el).val(newValue);
}

如果你不想四舍五入，请使用下面的函数。

function ConvertToDecimal(num) {
    num = num.toString(); //If it's not already a String
    num = num.slice(0, (num.indexOf(".")) + 3); //With 3 exposing the hundredths place
   alert('M : ' +  Number(num)); //If you need it back as a Number    
}

如果你的目标是解析，你的输入可能是一个文字，那么你会期望一个浮点数，而toFixed不会提供这个，所以这里有两个简单的函数来提供这个:

function parseFloat2Decimals(value) {
    return parseFloat(parseFloat(value).toFixed(2));
}

function parseFloat2Decimals(value,decimalPlaces) {
    return parseFloat(parseFloat(value).toFixed(decimalPlaces));
}