Example program. To begin we introduce 2 functions, uppercase_first and uppercase_words. These functions receive a str reference, and then return a new String.
Note In uppercase_first, we call to_ascii_uppercase() on the first char in the string. Other chars are left unchanged.
Note 2 In uppercase_words, we call to_ascii_uppercase() on the first char in the string. Any chars after a space are also considered first chars.
fn uppercase_first(data: &str) -> String {
// Uppercase first letter.
let mut result = String::new();
let mut first = true;
for value in data.chars() {
if first {
result.push(value.to_ascii_uppercase());
first = false;
} else {
result.push(value);
}
}
result
}
fn uppercase_words(data: &str) -> String {
// Uppercase first letter in string, and letters after spaces.
let mut result = String::new();
let mut first = true;
for value in data.chars() {
if first {
result.push(value.to_ascii_uppercase());
first = false;
} else {
result.push(value);
if value == ' ' {
first = true;
}
}
}
result
}
fn main() {
let test = "bird frog";
println!("UPPERCASE FIRST: {}", uppercase_first(test));
println!("UPPERCASE_WORDS: {}", uppercase_words(test));
}UPPERCASE FIRST: Bird frog
UPPERCASE_WORDS: Bird Frog
A summary. Many functions in Rust, like those used for implementing the uppercasing of first letters, are about the same as in other languages. Str reference arguments are important to understand.
Dot Net Perls is a collection of tested code examples. Pages are continually updated to stay current, with code correctness a top priority.
Sam Allen is passionate about computer languages. In the past, his work has been recommended by Apple and Microsoft and he has studied computers at a selective university in the United States.
