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Fixed mistakes and missing semicolon in string

This commit is contained in:
Tanish-Eagle 2022-04-20 22:53:21 +05:30
parent 9f8d1ae0d5
commit c1b10e03cd
1 changed files with 31 additions and 31 deletions
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62
en/src/compound-types/string.md
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@ -1,17 +1,17 @@
# string # String
The type of string literal `"hello, world"` is `&str`, e.g `let s: &str = "hello, world"`. The type of string literal `"hello, world"` is `&str`, e.g `let s: &str = "hello, world"`.
### str and &str ### Str and &str
1. 🌟 We can't use `str` type in normal ways, but we can use `&str` 1. 🌟 We can't use `str` type in normal ways, but we can use `&str`.
```rust,editable ```rust,editable
// fix error without adding new line // Fix error without adding new line
fn main() { fn main() {
let s: str = "hello, world"; let s: str = "hello, world";
println!("Success!") println!("Success!");
} }
``` ```
@ -20,7 +20,7 @@ fn main() {
```rust,editable ```rust,editable
// fix the error with at least two solutions // Fix the error with at least two solutions
fn main() { fn main() {
let s: Box<str> = "hello, world".into(); let s: Box<str> = "hello, world".into();
greetings(s) greetings(s)
@ -37,7 +37,7 @@ fn greetings(s: &str) {
3. 🌟 3. 🌟
```rust,editable ```rust,editable
// fill the blank // Fill the blank
fn main() { fn main() {
let mut s = __; let mut s = __;
s.push_str("hello, world"); s.push_str("hello, world");
@ -45,28 +45,28 @@ fn main() {
assert_eq!(s, "hello, world!"); assert_eq!(s, "hello, world!");
println!("Success!") println!("Success!");
} }
``` ```
4. 🌟🌟🌟 4. 🌟🌟🌟
```rust,editable ```rust,editable
// fix all errors without adding newline // Fix all errors without adding newline
fn main() { fn main() {
let s = String::from("hello"); let s = String::from("hello");
s.push(','); s.push(',');
s.push(" world"); s.push(" world");
s += "!".to_string(); s += "!".to_string();
println!("{}", s) println!("{}", s);
} }
``` ```
5. 🌟🌟 `replace` can be used to replace substring 5. 🌟🌟 `replace` can be used to replace substring
```rust,editable ```rust,editable
// fill the blank // Fill the blank
fn main() { fn main() {
let s = String::from("I like dogs"); let s = String::from("I like dogs");
// Allocate new memory and store the modified string there // Allocate new memory and store the modified string there
@ -74,17 +74,17 @@ fn main() {
assert_eq!(s1, "I like cats"); assert_eq!(s1, "I like cats");
println!("Success!") println!("Success!");
} }
``` ```
More `String` methods can be found under [String](https://doc.rust-lang.org/std/string/struct.String.html) module. More `String` methods can be found under [String](https://doc.rust-lang.org/std/string/struct.String.html) module.
6. 🌟🌟 You can only concat a `String` with `&str`, and `String`'s ownership can be moved to another variable 6. 🌟🌟 You can only concat a `String` with `&str`, and `String`'s ownership can be moved to another variable.
```rust,editable ```rust,editable
// fix errors without removing any line // Fix errors without removing any line
fn main() { fn main() {
let s1 = String::from("hello,"); let s1 = String::from("hello,");
let s2 = String::from("world!"); let s2 = String::from("world!");
@ -100,7 +100,7 @@ Opsite to the seldom using of `str`, `&str` and `String` are used everywhere!
7. 🌟🌟 `&str` can be converted to `String` in two ways 7. 🌟🌟 `&str` can be converted to `String` in two ways
```rust,editable ```rust,editable
// fix error with at lest two solutions // Fix error with at least two solutions
fn main() { fn main() {
let s = "hello, world"; let s = "hello, world";
greetings(s) greetings(s)
@ -115,25 +115,25 @@ fn greetings(s: String) {
```rust,editable ```rust,editable
// use two approaches to fix the error and without adding a new line // Use two approaches to fix the error and without adding a new line
fn main() { fn main() {
let s = "hello, world".to_string(); let s = "hello, world".to_string();
let s1: &str = s; let s1: &str = s;
println!("Success!") println!("Success!");
} }
``` ```
### string escapes ### String escapes
9. 🌟 9. 🌟
```rust,editable ```rust,editable
fn main() { fn main() {
// You can use escapes to write bytes by their hexadecimal values // You can use escapes to write bytes by their hexadecimal values
// fill the blank below to show "I'm writing Rust" // Fill the blank below to show "I'm writing Rust"
let byte_escape = "I'm writing Ru\x73__!"; let byte_escape = "I'm writing Ru\x73__!";
println!("What are you doing\x3F (\\x3F means ?) {}", byte_escape); println!("What are you doing\x3F (\\x3F means ?) {}", byte_escape);
// ...or Unicode code points. // ...Or Unicode code points.
let unicode_codepoint = "\u{211D}"; let unicode_codepoint = "\u{211D}";
let character_name = "\"DOUBLE-STRUCK CAPITAL R\""; let character_name = "\"DOUBLE-STRUCK CAPITAL R\"";
@ -169,11 +169,11 @@ fn main() {
let long_delimiter = __; let long_delimiter = __;
assert_eq!(long_delimiter, "Hello, \"##\""); assert_eq!(long_delimiter, "Hello, \"##\"");
println!("Success!") println!("Success!");
} }
``` ```
### byte string ### 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! 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**: **Example**:
@ -189,8 +189,8 @@ fn main() {
// Byte strings can have byte escapes... // Byte strings can have byte escapes...
let escaped = b"\x52\x75\x73\x74 as bytes"; let escaped = b"\x52\x75\x73\x74 as bytes";
// ...but no unicode escapes // ...But no unicode escapes
// let escaped = b"\u{211D} is not allowed"; // let escaped = b"\u{211D} Is not allowed";
println!("Some escaped bytes: {:?}", escaped); println!("Some escaped bytes: {:?}", escaped);
@ -207,7 +207,7 @@ fn main() {
like with normal raw strings"#; like with normal raw strings"#;
// Byte strings don't have to be UTF-8 // Byte strings don't have to be UTF-8
let shift_jis = b"\x82\xe6\x82\xa8\x82\xb1\x82\xbb"; // "ようこそ" in SHIFT-JIS let shift_jis = b"\x82\xe6\x82\xa8\x82\xb1\x82\xbb"; // "ようこそ" In SHIFT-JIS
// But then they can't always be converted to `str` // But then they can't always be converted to `str`
match str::from_utf8(shift_jis) { match str::from_utf8(shift_jis) {
@ -219,29 +219,29 @@ fn main() {
A more detailed listing of the ways to write string literals and escape characters is given in the ['Tokens' chapter](https://doc.rust-lang.org/reference/tokens.html) of the Rust Reference. A more detailed listing of the ways to write string literals and escape characters is given in the ['Tokens' chapter](https://doc.rust-lang.org/reference/tokens.html) of the Rust Reference.
### string index ### String index
11. 🌟🌟🌟 You can't use index to access a char in a string, but you can use slice `&s1[start..end]`. 11. 🌟🌟🌟 You can't use index to access a char in a string, but you can use slice `&s1[start..end]`.
```rust,editable ```rust,editable
fn main() { fn main() {
let s1 = String::from("hi,中国"); let s1 = String::from("hi,中国");
let h = s1[0]; //modify this line to fix the error, tips: `h` only takes 1 byte in UTF8 format let h = s1[0]; // Modify this line to fix the error, tips: `h` only takes 1 byte in UTF8 format
assert_eq!(h, "h"); assert_eq!(h, "h");
let h1 = &s1[3..5];//modify this line to fix the error, tips: `中` takes 3 bytes in UTF8 format let h1 = &s1[3..5]; // Modify this line to fix the error, tips: `中` takes 3 bytes in UTF8 format
assert_eq!(h1, "中"); assert_eq!(h1, "中");
println!("Success!") println!("Success!");
} }
``` ```
### operate on UTF8 string ### Operate on UTF8 string
12. 🌟 12. 🌟
```rust,editable ```rust,editable
fn main() { fn main() {
// fill the blank to print each char in "你好，世界" // Fill the blank to print each char in "你好，世界"
for c in "你好，世界".__ { for c in "你好，世界".__ {
println!("{}", c) println!("{}", c)
} }