[Solved] Given this Angular reactive form control initialization:this.form = new FormGroup({ username: new FormControl('', Validators.... | Angular

Angular - Reactive Forms

Given this Angular reactive form control initialization:

this.form = new FormGroup({
  username: new FormControl('', Validators.required)
});

// User focuses on username input, types 'John', then leaves the input.

What will be the values of dirty, touched, and valid for username after these actions?

A<code>dirty: true, touched: true, valid: false</code>

B<code>dirty: false, touched: true, valid: true</code>

C<code>dirty: true, touched: false, valid: false</code>

D<code>dirty: true, touched: true, valid: true</code>

Step-by-Step Solution

Solution:

Step 1: Analyze user actions on the form control
User focused and left the input, so touched is true. User changed the value from empty string to 'John', so dirty is true.
Step 2: Check validation status
The control has Validators.required. Since 'John' is not empty, the control is valid, so valid is true.
Final Answer:
dirty: true, touched: true, valid: true -> Option D
Quick Check:
Changed + left + valid input = dirty, touched, valid true [OK]

Quick Trick: Changed input + left focus + valid value = all true [OK]

Common Mistakes:

MISTAKES

Assuming dirty is false if user leaves input
Confusing touched with dirty
Thinking valid is false if user typed anything

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More Angular Quizzes

Given this Angular reactive form control initialization:

Step 1: Analyze user actions on the form control

Step 2: Check validation status

Final Answer:

Quick Check:

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