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

id, title, challengeType, videoUrl, forumTopicId

id	title	challengeType	videoUrl	forumTopicId
56bbb991ad1ed5201cd392cf	Write Reusable JavaScript with Functions	1	https://scrimba.com/c/cL6dqfy	18378

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');
  - text: <code>reusableFunction</code> should output "Hi World" to the dev console.
    testString: assert(hiWorldWasLogged);
  - text: You should call <code>reusableFunction</code> after you define it.
    testString: assert(/^\s*reusableFunction\(\)\s*/m.test(code));

Challenge Seed

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();