如何解决“'number' 类型的参数不能分配给'string | RegExp' 类型的参数。”

Question

I created a form in Angular and im trying to prevent the user from typing 'e' as a number. I know i have to convert the user input into a string first, and then check for 'e', then turn it back to a number.

(I was also wondering how I can replace that 'e' into an empty string so it doesn't show up on the input text)

this.signupForm = new FormGroup({
      'accountType': new FormControl('Personal', Validators.required),
      'name': new FormControl(null),
      'email': new FormControl(null,[Validators.required, Validators.email]),
      'city': new FormControl(null),
      'country': new FormControl(null, Validators.required),
      'zipCode': new FormControl(null, [Validators.pattern("[0-9]*"), Validators.pattern(e*), Validators.maxLength(5)]), 
      'dia': new FormControl(null)

    });

Answer 1

The validators only impact on the validity of the form, as follows:

// True if it complies with the validators, False if not
this.signupForm.valid

If what you want to do is restrict the input, you should do something like this:

In the component.ts:

public inputValidator(event: any) {
    this.signupForm.controls['zipCode'].setValue(event.target.value.replace(/[^0-9]*/g, "")); 
  }

Then in the html:

<input formControlName="zipCode" (input)="inputValidator($event)" type="text" maxlength="5" >

the "e" validator is not necessary because the regular ([Validators.pattern("[0-9]*")) expression already filters it