Text Input for Positive Integers Only

Question

I'm trying to make a number input that is for only positive numbers. I have the following html:

<button class="minus-btn" (click)="minus()" type="button" name="button">

<img src="../assets/images/minus.svg" alt="minus" />

</button>

<input ng-pattern="^(0|\+?[1-9]\d*)$" class="num" name="quantity" [value]="quantity" type="number" min="0">

<button class="plus-btn" (click)="plus()" type="button" name="button">

<img src="../assets/images/plus.svg" alt="plus" /></button>

As you can see, I've implemented ng-pattern and min value but neither one works. In the controller:

quantity: number=1;

i=1;

plus(){

this.i++;

this.quantity=this.i;

}

minus(){

this.i--;

this.quantity=this.i;

}

When I add the following to the controller, I get the error " Property 'match' does not exist on type 'number'"

this.quantity.match(/^(0|\+?[1-9]\d*)$/g);