Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
693 views
in Technique[技术] by (71.8m points)

int - How do I convert from an integer to a string?

I am unable to compile code that converts a type from an integer to a string. I'm running an example from the Rust for Rubyists tutorial which has various type conversions such as:

"Fizz".to_str() and num.to_str() (where num is an integer).

I think the majority (if not all) of these to_str() function calls have been deprecated. What is the current way to convert an integer to a string?

The errors I'm getting are:

error: type `&'static str` does not implement any method in scope named `to_str`
error: type `int` does not implement any method in scope named `to_str`

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

Use to_string() (running example here):

let x: u32 = 10;
let s: String = x.to_string();
println!("{}", s);

You're right; to_str() was renamed to to_string() before Rust 1.0 was released for consistency because an allocated string is now called String.

If you need to pass a string slice somewhere, you need to obtain a &str reference from String. This can be done using & and a deref coercion:

let ss: &str = &s;   // specifying type is necessary for deref coercion to fire
let ss = &s[..];     // alternatively, use slicing syntax

The tutorial you linked to seems to be obsolete. If you're interested in strings in Rust, you can look through the strings chapter of The Rust Programming Language.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...