Day 12 String Methods
Strings ke saath kaam karna web development mein roz hota hai — user input process karna, text format karna, search karna. Yeh methods yaad kar lo.
Common String Methods
Most used string methods with examples.
let str = " Hello, CodingSkillUp! ";
console.log(str.length); // 25
console.log(str.trim()); // "Hello, CodingSkillUp!"
console.log(str.toUpperCase()); // " HELLO, CODINGSKILLUP! "
console.log(str.toLowerCase()); // " hello, codingskillup! "
let clean = str.trim();
console.log(clean.includes("Coding")); // true
console.log(clean.startsWith("Hello")); // true
console.log(clean.endsWith("!")); // true
// Replace
console.log(clean.replace("CodingSkillUp", "World"));
// "Hello, World!"
// Repeat
console.log("ha".repeat(3)); // "hahaha"
slice, split, join
Text cut karna, array mein convert karna, aur join karna.
let text = "JavaScript is awesome";
// slice(start, end)
console.log(text.slice(0, 10)); // "JavaScript"
console.log(text.slice(-7)); // "awesome"
// split — string to array
let words = text.split(" ");
console.log(words); // ["JavaScript", "is", "awesome"]
// join — array to string
console.log(words.join("-")); // "JavaScript-is-awesome"
// Practical: CSV parse karna
let csv = "Ahmed,25,Lahore,Developer";
let [name, age, city, job] = csv.split(",");
console.log(name, city); // Ahmed Lahore
Template Literals
Backticks ` ` se multi-line strings aur variables embed karo.
let name = "Zohaib";
let score = 95;
let grade = "A";
// Template literal
let message = `
Student Report:
Name: ${name}
Score: ${score}/100
Grade: ${grade}
Status: ${score >= 50 ? "Pass" : "Fail"}
`;
console.log(message);
console.log(`2 + 2 = ${2 + 2}`); // outputs: 2 + 2 = 4
🎯 Practice Challenge
Email validator banao — check karo ke email mein @ aur . hai, space nahi hai, aur 5+ characters ka hai.