CODE EXAMPLE FOR JAVASCRIPT

angular validation on numbers

import { Component } from '@angular/core';
import { FormBuilder, FormGroup, Validators } from '@angular/forms';
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
  registerForm: FormGroup;
  submitted = false;
  constructor(private formBuilder: FormBuilder) { }
  //only number will be add
  keyPress(event: any) {
    const pattern = /[0-9+- ]/;
    let inputChar = String.fromCharCode(event.charCode);
    if (event.keyCode != 8 && !pattern.test(inputChar)) {
      event.preventDefault();
    }
  }
  ngOnInit() {
    this.registerForm = this.formBuilder.group({
      phonenumber: ['', [ Validators.required,
        Validators.pattern("^[0-9]*$"),
        Validators.minLength(10), Validators.maxLength(10)]]
    });
}
// convenience getter for easy access to form fields
get f() { return this.registerForm.controls; }
onSubmit() {
  this.submitted = true;
  // stop here if form is invalid
  if (this.registerForm.invalid) {
    return;
  }

}

}