More detail about expression and statement

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Michael-Lai fx 2018-10-11 16:56:06 +08:00 committed by GitHub
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1 changed files with 5 additions and 2 deletions

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@ -40,5 +40,8 @@ fn square(num: i32) -> i32 {
// This is a really common error that can be fixed by removing one character.
// It happens because Rust distinguishes between expressions and statements: expressions return
// a value and statements don't. We want to return a value from the `square` function, but it
// isn't returning one right now...
// a value based on its operand and statements simply retun a `()` type which just like `void` in C/C++ language.
// We want to return a value of `i32` type from the `square` function, but it is returning a `()` type...
// They are not the same. There are two solusions:
// 1. Add a `return` ahead of `num * num;`
// 2. remove `;`, make it to be `num * num`