don't allow e in number input using regular expression in angular code example
Example 1: angular numbers only directive
import { Directive, ElementRef, HostListener, Input } from '@angular/core';
import { NgControl } from '@angular/forms';
@Directive({
selector: 'input[type=number], input[numbersOnly]'
})
export class NumbersOnlyInputDirective {
constructor(private elRef: ElementRef) { }
@HostListener('input', ['$event']) onInputChange(event) {
const initalValue = this.elRef.nativeElement.value;
this.elRef.nativeElement.value = initalValue.replace(/[^0-9]*/g, '');
if ( initalValue !== this.elRef.nativeElement.value) {
event.stopPropagation();
}
}
}
Example 2: numeric key angular validation
@HostListener('keydown', ['$event'])onKeyDown(e: KeyboardEvent) { if ( // Allow: Delete, Backspace, Tab, Escape, Enter, etc this.navigationKeys.indexOf(e.key) > -1 || (e.key === 'a' && e.ctrlKey === true) || // Allow: Ctrl+A (e.key === 'c' && e.ctrlKey === true) || // Allow: Ctrl+C (e.key === 'v' && e.ctrlKey === true) || // Allow: Ctrl+V (e.key === 'x' && e.ctrlKey === true) || // Allow: Ctrl+X (e.key === 'a' && e.metaKey === true) || // Cmd+A (Mac) (e.key === 'c' && e.metaKey === true) || // Cmd+C (Mac) (e.key === 'v' && e.metaKey === true) || // Cmd+V (Mac) (e.key === 'x' && e.metaKey === true) // Cmd+X (Mac) ) { return; // let it happen, don't do anything } // Ensure that it is a number and stop the keypress if (e.key === ' ' || isNaN(Number(e.key))) { e.preventDefault(); }}