list of the most common JavaScript string methods:
- length:
let message = "Hello, world!";
console.log(message.length); // Output: 13
- concat():
let greeting = "Hello";
let name = "Alice";
let fullGreeting = greeting.concat(", ", name, "!");
console.log(fullGreeting); // Output: "Hello, Alice!"
- charAt():
let message = "JavaScript";
console.log(message.charAt(0)); // Output: "J"
console.log(message.charAt(5)); // Output: "S"
- indexOf():
let sentence = "The quick brown fox jumps over the lazy dog.";
console.log(sentence.indexOf("quick")); // Output: 4
console.log(sentence.indexOf("dog")); // Output: 37
console.log(sentence.indexOf("lion")); // Output: -1 (not found)
- lastIndexOf():
let quote = "To be, or not to be, that is the question.";
console.log(quote.lastIndexOf("be")); // Output: 23
console.log(quote.lastIndexOf("the")); // Output: 33
- slice():
let fruit = "apple, banana, cherry";
console.log(fruit.slice(0, 5)); // Output: "apple"
console.log(fruit.slice(7, 13)); // Output: "banana"
console.log(fruit.slice(15)); // Output: "cherry"
- substring():
let text = "Hello, world!";
console.log(text.substring(0, 5)); // Output: "Hello"
console.log(text.substring(7, 12)); // Output: "world"
- substr():
let message = "The quick brown fox jumps.";
console.log(message.substr(4, 5)); // Output: "quick"
console.log(message.substr(10)); // Output: "brown fox jumps."
- toLowerCase():
let text = "JAVASCRIPT IS AWESOME!";
console.log(text.toLowerCase()); // Output: "javascript is awesome!"
- toUpperCase():
let text = "hello, world!";
console.log(text.toUpperCase()); // Output: "HELLO, WORLD!"
- trim():
let greeting = " Hello, world! ";
console.log(greeting.trim()); // Output: "Hello, world!"
- replace():
let text = "I like cats. Cats are fluffy.";
console.log(text.replace("cats", "dogs")); // Output: "I like dogs. Cats are fluffy."
console.log(text.replace(/cats/i, "dogs")); // Output: "I like dogs. Cats are fluffy." (case-insensitive)
- split():
let csv = "apple,banana,cherry";
let fruits = csv.split(",");
console.log(fruits); // Output: ["apple", "banana", "cherry"]
- includes():
let message = "The quick brown fox jumps over the lazy dog.";
console.log(message.includes("quick")); // Output: true
console.log(message.includes("tiger")); // Output: false
- startsWith():
let greeting = "Hello, world!";
console.log(greeting.startsWith("Hello")); // Output: true
console.log(greeting.startsWith("world")); // Output: false
- endsWith():
let filename = "myfile.pdf";
console.log(filename.endsWith(".pdf")); // Output: true
console.log(filename.endsWith(".txt")); // Output: false
- match():
let text = "The quick brown fox jumps.";
let pattern = /quick/;
console.log(text.match(pattern)); // Output: ["quick"]
- search():
let text = "The quick brown fox jumps.";
let pattern = /brown/;
console.log(text.search(pattern)); // Output: 10
- repeat():
let message = "Hello ";
console.log(message.repeat(3)); // Output: "Hello Hello Hello "
- trimStart():
let greeting = " Hello, world! ";
console.log(greeting.trimStart()); // Output: "Hello, world! "
- trimEnd():
let greeting = " Hello, world! ";
console.log(greeting.trimEnd()); // Output: " Hello, world!"
- padStart():
let number = "42";
console.log(number.padStart(4, "0")); // Output: "0042"
padEnd():
let word = "JavaScript";
console.log(word.padEnd(15, ".")); // Output: "JavaScript....."splice():
let str = "Hello, world!";
let result = str.splice(7, 5, "everyone");
console.log(result); // Output: "world"
console.log(str); // Output: "Hello, everyone!"
- toString():
let num = 42;
console.log(num.toString()); // Output: "42"
- valueOf():
let str = "JavaScript";
console.log(str.valueOf()); // Output: "JavaScript"
- charCodeAt():
let message = "Hello";
console.log(message.charCodeAt(0)); // Output: 72
console.log(message.charCodeAt(4)); // Output: 111
- codePointAt():
let emoji = "😀";
console.log(emoji.codePointAt(0)); // Output: 128512
normalize():
let str1 = "café";
let str2 = "cafe\u0301";
console.log(str1.normalize() === str2.normalize()); // Output: true
This covers a wide range of string manipulation tasks in JavaScript, from basic operations like getting the length or concatenating strings to more advanced techniques like pattern matching and Unicode normalization.
Top comments (0)