Gist Quickie! Random Array Constructor in JS

Create randomized arrays for testing

function RandomArray(opts = {}) {
  this.alphabet = 'abcdefghijklmnopqrstuvwxyz'; 
  this.type = opts.type || 'number';
  this.length = opts.length || 100;
  this.max = opts.max || 100;
  this.min = opts.min || 0;
  
  this.getRandomEntry = () => {
    switch(this.type.toLowerCase()) {
      case 'letters':
        return this.alphabet.charAt(Math.floor(Math.random() * this.alphabet.length));
      case 'number':
      default:
        return Math.floor(Math.random() * (this.max - this.min) + this.min);
    }
  }
  
  return Array.from({length: this.length}, this.getRandomEntry.bind(this));
}

const testA = new RandomArray();
console.log(testA); // [55, 5, 43, 56, 28, ... ] 

const testB = new RandomArray({length: 50, max: 23, min: 10});
console.log(testB); // [18, 17, 10, 18 ... ] 

const testC = new RandomArray({lenght: 30, type: 'letters'});
console.log(testC); //["k", "l", "f", "p", "r", ... ] 

try it!