JavaScript Strings
A string in JavaScript is a sequence of characters used to store and work with text.
What is a String?
Strings hold text: a name, a sentence, a URL, or even a single character. You create a string by wrapping characters in quotes. JavaScript accepts three kinds of quotes, and all of them produce the same type of value — a primitive string.
- Double quotes: "Hello world"
- Single quotes: 'Hello world'
- Backticks (template literals): `Hello world`
- The quotes you open with must match the quotes you close with.
Creating strings
<!DOCTYPE html>
<html>
<body>
<h2>Creating strings</h2>
<script>
let greeting = "Hello";
let name = 'Ada';
let phrase = `Learning JavaScript`;
console.log(greeting); // Hello
console.log(name); // Ada
console.log(phrase); // Learning JavaScript
</script>
</body>
</html>When your text itself contains a quote character, you can either use a different quote style on the outside, or escape the inner quote with a backslash. The backslash tells JavaScript to treat the next character as plain text rather than as the end of the string.
Quotes inside strings and escaping
<!DOCTYPE html>
<html>
<body>
<h2>Quotes inside strings and escaping</h2>
<script>
let a = "It's a sunny day"; // single quote inside double quotes
let b = 'She said "hi" to me'; // double quote inside single quotes
let c = 'It\'s escaped'; // backslash escapes the quote
let d = "Line one\nLine two"; // \n adds a new line
console.log(c); // It's escaped
</script>
</body>
</html>You can read the number of characters in a string with .length, and reach any single character by its index using bracket notation or the charAt() method.
Length and accessing characters
<!DOCTYPE html>
<html>
<body>
<h2>Length and accessing characters</h2>
<script>
let word = "JavaScript";
console.log(word.length); // 10
console.log(word[0]); // J
console.log(word[4]); // S
console.log(word.charAt(1)); // a
</script>
</body>
</html>Exercise: JavaScript Strings
Can you change a single character of a string in place?
