password and confirm password field validation angular2 reactive forms

Question

I need to check whether password and confirm password fields have same value using reactive form angular2. I did see a lot of answers on the same here,Angular 2 form validating for repeat password ,Comparing fields in validator with angular2, but none seemed to work for me.Can someone please help."this" is undefined in my validate function :( . Sharing my code,

this.addEditUserForm = this.builder.group({             firstName: ['', Validators.required],             lastName: ['', Validators.required],             title: ['', Validators.required],             email: ['', Validators.required],             password: ['', Validators.required],             confirmPass: ['', [Validators.required, this.validatePasswordConfirmation]]         }); validatePasswordConfirmation(group: FormGroup): any{         let valid = true;         // if (this.addEditUserForm.controls.password != this.addEditUserForm.controls.confirmPass) {         //     valid = false;         //     this.addEditUserForm.controls.confirmPass.setErrors({validatePasswordConfirmation: true});         // }         return valid;     } 

Answer 1

This is what eventually worked for me -

this.addEditUserForm = this.builder.group({             firstName: ['', Validators.required],             lastName: ['', Validators.required],             title: ['', Validators.required],             email: ['', Validators.required],             password: ['', Validators.required],             confirmPass: ['', Validators.required]         },{validator: this.checkIfMatchingPasswords('password', 'confirmPass')});    checkIfMatchingPasswords(passwordKey: string, passwordConfirmationKey: string) {           return (group: FormGroup) => {             let passwordInput = group.controls[passwordKey],                 passwordConfirmationInput = group.controls[passwordConfirmationKey];             if (passwordInput.value !== passwordConfirmationInput.value) {               return passwordConfirmationInput.setErrors({notEquivalent: true})             }             else {                 return passwordConfirmationInput.setErrors(null);             }           }         }