angular formcontrol have required validator code example

Example 1: how to add validator to formgroup

this.myForm = this.formBuilder.group({
        myControl1: this.defaultValue,
        myControl2: this.defaultValue
      });
      debugger
      this.myForm.setValidators(this.comparisonValidator())
}

 public comparisonValidator() : ValidatorFn{
       return (group: FormGroup): ValidationErrors => {
          const control1 = group.controls['myControl1'];
          const control2 = group.controls['myControl2'];
          if (control1.value !== control2.value) {
             control2.setErrors({notEquivalent: true});
          } else {
             control2.setErrors(null);
          }
          return;
    };

Example 2: angular check if control has required validator

import { AbstractControl } from '@angular/forms';

export const isControlRequired = (control: AbstractControl): boolean => {
  if (!control) {
    return false;
  }

  if (control.validator) {
    const validator = control.validator({} as AbstractControl);
    if (validator && validator.required) {
      return true;
    }
  }

  return false;
};