Strings

In JavaScript, strings are a primitive data type used to represent textual data. They are sequences of characters,

String methods and properties

JavaScript provides various built-in methods and properties for working with strings, including:

• length: Returns the number of characters in the string.
• indexOf() and includes(): For searching within strings.
• slice(), substring(), and substr(): For extracting parts of a string.
• toUpperCase() and toLowerCase(): For case conversion.
• trim(): For removing whitespace from ends.
• split(): For splitting a string into an array.
• replace(): For replacing parts of a string.

Creating strings

Strings can be created using single quotes:

'Hello'

Strings can also be created using double quotes:

"World"

html and javascript

When combining JavaScript and HTML, it is a good idea to use one style of quotes for JavaScript and the other style for HTML:

<button onclick="alert('Thank you')">Click Me</button>

But using backticks gives you enhanced features like multiline strings and embedded expressions using $. The final value of a string literal in backticks is computed by evaluating included expressions, converting values to strings and combining with the literal characters:

let name = "Bob";

let greeting = `Hello ${ name }`;  

Immutability

Once a string is created, its content cannot be directly modified. String methods that appear to modify a string, such as toUpperCase(), slice() or concat(), actually return a new string with the desired changes.

Indexing

Characters within a string can be accessed by their index, starting from 0 for the first character. To access individual characters:

myString[0]
myString[myString.length-1]

No Character Type:

Unlike some other languages, JavaScript does not have a separate char data type; single characters are simply strings of length one.

Escape Sequences

Special characters like quotation marks within a string can be included using escape sequences, such as \" for a double quote or \' for a single quote. Backslashes themselves are escaped with \\.

String concat

Concatenate strings with + operator:

    let firstName = "John";
    let lastName = "Doe";
    let fullName = firstName + " " + lastName; // "John Doe"

However, strings can also be contenated by using backticks:

    let greeting = "Hello";
    let name = "Alice";
    let message = `${greeting} ${name}!`; // "Hello, Alice!"

String compare

Compare strings with === and !== for equality/inequality.

Order strings using: <, <=, <, >=.