是否可以在 Rust for 循环中声明变量的类型? [英] Is it possible to declare the type of the variable in Rust for loops?

问题描述

C++ 示例:

for (long i = 0; i < 101; i++) {
    //...
}

在 Rust 中我尝试过:

In Rust I tried:

for i: i64 in 1..100 {
    // ...
}

我可以很容易地在 for 循环之前声明一个 let i: i64 = var但我宁愿学习正确的方法来做到这一点，但这导致

I could easily just declare a let i: i64 = var before the for loop but I'd rather learn the correct way to doing this, but this resulted in

error: expected one of `@` or `in`, found `:`
 --> src/main.rs:2:10
  |
2 |     for i: i64 in 1..100 {
  |          ^ expected one of `@` or `in` here

推荐答案

您可以使用 整数后缀 在您在该范围内使用的文字之一上.类型推断将完成剩下的工作:

You can use an integer suffix on one of the literals you've used in the range. Type inference will do the rest:

for i in 1i64..101 {
    println!("{}", i);
}

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