freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/passing-values-to-functions-with-arguments.english.md

id	title	challengeType
56533eb9ac21ba0edf2244bd	Passing Values to Functions with Arguments	1

Description

Parameters are variables that act as placeholders for the values that are to be input to a function when it is called. When a function is defined, it is typically defined along with one or more parameters. The actual values that are input (or "passed") into a function when it is called are known as arguments. Here is a function with two parameters, param1 and param2:

function testFun(param1, param2) {
  console.log(param1, param2);
}

Then we can call testFun: testFun("Hello", "World"); We have passed two arguments, "Hello" and "World". Inside the function, param1 will equal "Hello" and param2 will equal "World". Note that you could call testFun again with different arguments and the parameters would take on the value of the new arguments.

Instructions

1. Create a function called functionWithArgs that accepts two arguments and outputs their sum to the dev console.
2. Call the function with two numbers as arguments.

Tests

tests:
  - text: <code>functionWithArgs</code> should be a function
    testString: assert(typeof functionWithArgs === 'function', '<code>functionWithArgs</code> should be a function');
  - text: <code>functionWithArgs(1,2)</code> should output <code>3</code>
    testString: if(typeof functionWithArgs === "function") { capture(); functionWithArgs(1,2); uncapture(); } assert(logOutput == 3, '<code>functionWithArgs(1,2)</code> should output <code>3</code>');
  - text: <code>functionWithArgs(7,9)</code> should output <code>16</code>
    testString: if(typeof functionWithArgs === "function") { capture(); functionWithArgs(7,9); uncapture(); } assert(logOutput == 16, '<code>functionWithArgs(7,9)</code> should output <code>16</code>');
  - text: Call <code>functionWithArgs</code> with two numbers after you define it.
    testString: assert(/^\s*functionWithArgs\s*\(\s*\d+\s*,\s*\d+\s*\)\s*;/m.test(code), 'Call <code>functionWithArgs</code> with two numbers after you define it.');

Challenge Seed

// Example
function ourFunctionWithArgs(a, b) {
  console.log(a - b);
}
ourFunctionWithArgs(10, 5); // Outputs 5

// Only change code below this line.

Before Test

var logOutput = "";
var originalConsole = console
function capture() {
    var nativeLog = console.log;
    console.log = function (message) {
        if(message) logOutput = JSON.stringify(message).trim();
        if(nativeLog.apply) {
          nativeLog.apply(originalConsole, arguments);
        } else {
          var nativeMsg = Array.prototype.slice.apply(arguments).join(' ');
          nativeLog(nativeMsg);
        }
    };
}

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

capture();

After Test

uncapture();

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

Solution

function functionWithArgs(a, b) {
  console.log(a + b);
}
functionWithArgs(10, 5);