JSFiddle - React, Tailwind, and code Playground

JavaScript

var control = 'a.jpg';
var image_name = control;
var image = new Image();

image.onload = function() {
    control = true;
    after();
};
image.onerror = function() {		
    control = false;
    after();
};
image.src = image_name;

function after(){
		alert(control);
    console.log(control);
}