JSFiddle - React, Tailwind, and code Playground

JavaScript

var ranges = [ 
    { from: 11, image: "image4" }, 
    { from: 1, image: "image3" }, 
    { from: -9, image: "image2" }, 
    { from: -20, image: "image1" },             
]; 
 
var random_num = (Math.round((Math.random()*41)+-20)); 
var image = "default"; 
 
for(var i = 0; i < ranges.length; ++i) { 
    if(random_num >= ranges[i].from) { 
        image = ranges[i].image; 
        break; 
    } 
} 
 
alert("random_num = " + random_num + " / image = " + image);