freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/write-reusable-javascript-with-functions.english.md

id, title, challengeType, videoUrl

id	title	challengeType	videoUrl
56bbb991ad1ed5201cd392cf	Write Reusable JavaScript with Functions	1	https://scrimba.com/c/cL6dqfy

Description

In JavaScript, we can divide up our code into reusable parts called functions. Here's an example of a function:

function functionName() {
  console.log("Hello World");
}

You can call or invoke this function by using its name followed by parentheses, like this: functionName(); Each time the function is called it will print out the message "Hello World" on the dev console. All of the code between the curly braces will be executed every time the function is called.

Instructions

1. Create a function called reusableFunction which prints "Hi World" to the dev console.
2. Call the function.

Tests

tests:
  - text: <code>reusableFunction</code> should be a function
    testString: assert(typeof reusableFunction === 'function', '<code>reusableFunction</code> should be a function');
  - text: <code>reusableFunction</code> should output "Hi World" to the dev console
    testString: assert(hiWorldWasLogged, '<code>reusableFunction</code> should output "Hi World" to the dev console');
  - text: Call <code>reusableFunction</code> after you define it
    testString: assert(/^\s*reusableFunction\(\)\s*/m.test(code), 'Call <code>reusableFunction</code> after you define it');

Challenge Seed

// Example
function ourReusableFunction() {
  console.log("Heyya, World");
}

ourReusableFunction();

// Only change code below this line

Before Test

var logOutput = "";
var originalConsole = console;
var nativeLog = console.log;
var hiWorldWasLogged = false;
function capture() {
    console.log = function (message) {
        if(message === 'Hi World')  hiWorldWasLogged = true;
        if(message && message.trim) logOutput = message.trim();
        if(nativeLog.apply) {
          nativeLog.apply(originalConsole, arguments);
        } else {
          var nativeMsg = Array.prototype.slice.apply(arguments).join(' ');
          nativeLog(nativeMsg);
        }
    };
}

function uncapture() {
  console.log = nativeLog;
}

capture();

After Test

uncapture();

if (typeof reusableFunction !== "function") { 
  (function() { return "reusableFunction is not defined"; })();
} else {
  (function() { return logOutput || "console.log never called"; })();
}

Solution

function reusableFunction() {
  console.log("Hi World");
}
reusableFunction();