String

The type of string literal "hello, world" is &str, e.g let s: &str = "hello, world".

Str and &str

  1. 🌟 We can't use str type in normal ways, but we can use &str.
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  1. 🌟🌟 We can only use str by boxing it, & can be used to convert Box<str> to &str 
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String

String type is defined in std and stored as a vector of bytes (Vec), but guaranteed to always be a valid UTF-8 sequence. String is heap allocated, growable and not null terminated.

  1. 🌟
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  1. 🌟🌟🌟
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  1. 🌟🌟 replace can be used to replace substring
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More String methods can be found under String module.

  1. 🌟🌟 You can only concat a String with &str, and String's ownership can be moved to another variable.
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&str and String

Opposite to the seldom using of str, &str and String are used everywhere!

  1. 🌟🌟 &str can be converted to String in two ways
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  1. 🌟🌟 We can use String::from or to_string to convert a &str to String
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String escapes

  1. 🌟 
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  1. 🌟🌟🌟 Sometimes there are just too many characters that need to be escaped or it's just much more convenient to write a string out as-is. This is where raw string literals come into play.
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Byte string

Want a string that's not UTF-8? (Remember, str and String must be valid UTF-8). Or maybe you want an array of bytes that's mostly text? Byte strings to the rescue!

Example:

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A more detailed listing of the ways to write string literals and escape characters is given in the 'Tokens' chapter of the Rust Reference.

String index

  1. 🌟🌟🌟 You can't use index to access a char in a string, but you can use slice &s1[start..end].
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Operate on UTF8 string

  1. 🌟
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utf8_slice

You can use utf8_slice to slice UTF8 string, it can index chars instead of bytes.

Example

use utf8_slice;
fn main() {
    let s = "The 🚀 goes to the 🌑!";

    let rocket = utf8_slice::slice(s, 4, 5);
    // Will equal "🚀"
}

You can find the solutions here(under the solutions path), but only use it when you need it