JS Practice — Built-in Objects

Array.prototype.includes() — check for a word

📖 Usage Example

const colors = ['red', 'green', 'blue']
colors.includes('green')  // → true
colors.includes('yellow') // → false

Use includes() for a readable boolean check instead of indexOf() !== -1.

Array.prototype.includes() — strings

includes() works with any element type. It is the cleanest way to check if a string exists in an array of strings.

Challenge: Implement hasWord(words, word) that returns true if word is in the words array.

hasWord(['hello', 'world'], 'world') // → true
hasWord(['hello', 'world'], 'foo')   // → false

💡 Hints (2)