freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/understand-string-immutability.english.md

id, title, challengeType, isHidden, videoUrl, forumTopicId

id	title	challengeType	isHidden	videoUrl	forumTopicId
56533eb9ac21ba0edf2244ba	Understand String Immutability	1	false	https://scrimba.com/c/cWPVaUR	18331

Description

In JavaScript, String values are immutable, which means that they cannot be altered once created. For example, the following code:

var myStr = "Bob";
myStr[0] = "J";

cannot change the value of myStr to "Job", because the contents of myStr cannot be altered. Note that this does not mean that myStr cannot be changed, just that the individual characters of a string literal cannot be changed. The only way to change myStr would be to assign it with a new string, like this:

var myStr = "Bob";
myStr = "Job";

Instructions

Correct the assignment to myStr so it contains the string value of Hello World using the approach shown in the example above.

Tests

tests:
  - text: <code>myStr</code> should have a value of <code>Hello World</code>.
    testString: assert(myStr === "Hello World");
  - text: You should not change the code above the specified comment.
    testString: assert(/myStr = "Jello World"/.test(code));

Challenge Seed

// Setup
var myStr = "Jello World";

// Only change code below this line
myStr[0] = "H"; // Change this line
// Only change code above this line

After Test

(function(v){return "myStr = " + v;})(myStr);

Solution

var myStr = "Jello World";
myStr = "Hello World";