String Manipulation Methods

const str = 'hello world';
const result = str.replace(/\b\w/g, char => char.toUpperCase());

Converting to lowercase
Title case conversion
This code implements title case conversion: 1) Uses regex to match word boundaries followed by character, 2) Applies toUpperCase() to each matched character, 3) Creates proper title case formatting, 4) Handles multiple words in string, 5) Preserves non-first letters' case, 6) Common in text formatting and display, 7) Uses functional callback with replace(), 8) Efficient way to capitalize first letter of each word.
Random case changing
Letter replacement