JavaScript - 17

JavaScript - 17: String Methods

Strings have built-in methods and properties that help you work with text.

Your challenge: Use the text variable to create an uppercase version, find its length, check for a word, and replace part of the text.

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Convert text to uppercase

Use: text.toUpperCase()

This returns a new uppercase version of the string.

Find the string length

Use: text.length

The length includes letters, spaces, and punctuation.

Check whether text contains a word

Use: text.includes("JavaScript")

This returns either true or false.

Replace part of a string

Use: text.replace("JavaScript", "coding")

This creates a new version of the string with the selected word replaced.

Important: Methods such as .toUpperCase() and .replace() do not change the original string. They return a new string instead.

Try it: Change the original sentence and see how each result changes.

Small experiment: Try text.includes("learning"), then try the same word with different capitalization.

Good JavaScript habit: Remember that .length is a property, while methods such as .toUpperCase(), .includes(), and .replace() use parentheses.

👀 Show Solution
const text = "I love learning JavaScript!";

console.log("Uppercase:", text.toUpperCase());
console.log("Length:", text.length);
console.log("Contains JavaScript:", text.includes("JavaScript"));
console.log("Replaced:", text.replace("JavaScript", "coding"));

The four lines use the same original string to produce different results without changing the value stored in text.