String Formatting

String formatting in JavaScript is the process of constructing strings by embedding variables, expressions, or formatting values in a readable and maintainable way.

Common String Formatting Techniques

• Concatenation with + operator: Join strings and variables manually.
• Template Literals (Recommended): Use backticks ` ` with ${} to embed expressions.
• String methods: Use methods like padStart(), padEnd(), and toFixed() for specific formatting.

1. Concatenation

Old style method by joining strings with +:

const name = "Anna";
const age = 25;
const message = "Hello, " + name + "! You are " + age + " years old.";
console.log(message);

2. Template Literals

Modern and cleaner way to embed expressions inside strings using backticks and ${}:

const name = "Anna";
const age = 25;
const message = `Hello, ${name}! You are ${age} years old.`;
console.log(message);

3. Padding Strings

Use padStart() and padEnd() to add characters to a string until it reaches a desired length:

const id = "7";
console.log(id.padStart(4, "0")); // "0007"
console.log(id.padEnd(4, "."));   // "7..."

4. Number Formatting with toFixed()

Format numbers to fixed decimal places for consistent display:

const price = 9.8765;
console.log(price.toFixed(2)); // "9.88"