JavaScript Examples
Dave Braunschweig
Counting
// This program demonstrates While, Do, and For loop counting using // user-designated start, stop, and increment values. // // References: // https://en.wikibooks.org/wiki/JavaScript main() function main() { var start = getValue("starting"); var stop = getValue("ending"); var increment = getValue("increment"); demonstrateWhileLoop(start, stop, increment); demonstrateDoLoop(start, stop, increment); demonstrateForLoop(start, stop, increment); } function getValue(name) { output("Enter " + name + " value:"); var value = Number(input()); return value; } function demonstrateWhileLoop(start, stop, increment) { output("While loop counting from " + start + " to " + stop + " by " + increment + ":"); var count = start; while (count <= stop) { output(count); count = count + increment; } } function demonstrateDoLoop(start, stop, increment) { output("Do loop counting from " + start + " to " + stop + " by " + increment + ":"); var count = start; do { output(count); count = count + increment; } while (count <= stop); } function demonstrateForLoop(start, stop, increment) { output("For loop counting from " + start + " to " + stop + " by " + increment + ":"); for (var count = start; count <= stop; count += increment) { output(count); } } function input(text) { if (typeof window === 'object') { return prompt(text) } else if (typeof console === 'object') { const rls = require('readline-sync'); var value = rls.question(text); return value; } else { output(text); var isr = new java.io.InputStreamReader(java.lang.System.in); var br = new java.io.BufferedReader(isr); var line = br.readLine(); return line.trim(); } } function output(text) { if (typeof document === 'object') { document.write(text); } else if (typeof console === 'object') { console.log(text); } else { print(text); } }
Output
Enter starting value: 1 Enter ending value: 3 Enter increment value: 1 While loop counting from 1 to 3 by 1: 1 2 3 Do loop counting from 1 to 3 by 1: 1 2 3 For loop counting from 1 to 3 by 1: 1 2 3