69 lines
1.0 KiB
Markdown
69 lines
1.0 KiB
Markdown
1.
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```rust
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fn main() {
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let arr: [i32; 5] = [1, 2, 3, 4, 5];
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assert!(arr.len() == 5);
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}
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```
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2.
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```rust
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fn main() {
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// we can ignore parts of the array type or even the whole type, let the compiler infer it for us
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let arr0 = [1, 2, 3];
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let arr: [_; 3] = ['a', 'b', 'c'];
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// Arrays are stack allocated, `std::mem::size_of_val` return the bytes which array occupies
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// A char takes 4 byte in Rust: Unicode char
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assert!(std::mem::size_of_val(&arr) == 12);
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}
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```
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3.
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```rust
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fn main() {
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let list: [i32; 100] = [1; 100];
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assert!(list[0] == 1);
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assert!(list.len() == 100);
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}
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```
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4.
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```rust
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fn main() {
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// fix the error
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let _arr = [1, 2, 3];
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}
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```
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5.
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```rust
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fn main() {
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let arr = ['a', 'b', 'c'];
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let ele = arr[0];
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assert!(ele == 'a');
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}
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```
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6.
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```rust
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fn main() {
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let names = [String::from("Sunfei"), "Sunface".to_string()];
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// `get` returns an Option<T>, it's safe to use
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let name0 = names.get(0).unwrap();
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// but indexing is not safe
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let _name1 = &names[1];
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}
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``` |