JSFiddle - React, Tailwind, and code Playground

by gaby de wilde

JavaScript

nums = new Set(['1','2','3','4','5','6','7','8','9','0']);

hasOnlyNumbers=str=>[...str].every(x=>nums.has(x));

alert(      hasOnlyNumbers('3243234332')     );
alert(      hasOnlyNumbers('notnumbers')     );