Question

How to convert part of a string between two indexes to uppercase in Rust

Answer 1

fn convert_part_to_uppercase(s: &str, start: usize, end: usize) -> String {
    let before = &s[0..start];
    let upper_part = &s[start..end].to_uppercase();
    let after = &s[end..];

    format!("{}{}{}", before, upper_part, after)
}

fn main() {
    let mut s = String::from("rust programming");

    s = convert_part_to_uppercase(&s, 3, 6);
    println!("{}", s);

    s = convert_part_to_uppercase(&s, 11, 12);
    println!("{}", s);
}


  
/*
run:

rusT Programming
rusT PrograMming

*/

 

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