How does Rust handle string manipulation and what is the difference between String and &str types?

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Aryan Kumar · Answer

Rust handles string manipulation in a similar way to other programming languages, with a few key differences.

String literals are a special type of string that is statically allocated in the program's binary. This means that they cannot be changed after the program is compiled. String literals are denoted by using double quotes (") around the string, for example:

Rust

let hello_world = "Hello, world!";

String objects are a more flexible type of string that can be changed after the program is compiled. String objects are allocated in the heap, and they can grow or shrink as needed. String objects are created using the String::from() method, for example:

Rust

let mut hello_world = String::from("Hello, world!");
hello_world.push_str(" This is Rust");

The difference between string and &str

The string and &str types are two different ways to represent strings in Rust. string is a growable, heap-allocated type, while &str is a reference to a fixed-size, statically allocated string.

In general, you should use string if you need to be able to change the string, and you should use &str if you don't need to change the string.

Here is a table that summarizes the key differences between string and &str:

Feature	`string`	`&str`
Memory allocation	Heap	Stack
Size	Can grow or shrink	Fixed
Mutability	Mutable	Immutable
Ownership	Owns the string data	Borrows the string data

Here are some examples of string manipulation in Rust:

Getting the length of a string:

Rust

let hello_world = "Hello, world!";
let length = hello_world.len();

Converting a string to uppercase:

Rust

let hello_world = "Hello, world!";
let uppercase_hello_world = hello_world.to_uppercase();

Splitting a string into a vector of words:

Rust

let hello_world = "Hello, world!";
let words = hello_world.split(" ").collect();

Replacing all occurrences of a substring with another substring:

Rust

let hello_world = "Hello, world!";
let new_hello_world = hello_world.replace("world", "Rust");

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How does Rust handle string manipulation and what is the difference between String and &str types?

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