Detect when input value changed in directive

Question

I\'m trying to detect when the value of an input changed in a directive. I have the following directive:

Answer 1

You can also use HostListener. For more information about HostListener, you can go through this link. Here is the code.

import {Directive, ElementRef, HostListener} from '@angular/core';


@Directive({
       selector: '[number]'
 })

export class NumberDirective {

    @Input() public number: any;
    @Input() public input: any;

    constructor(private el: ElementRef) {}

    @HostListener('change') ngOnChanges() {
        console.log('test');
    }

}