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49 lines
1.4 KiB
Rust
49 lines
1.4 KiB
Rust
// iterators2.rs
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// In this module, you'll learn some of unique advantages that iterators can offer
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// Step 1. Complete the `capitalize_first` function to pass the first two cases
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// Step 2. Apply the `capitalize_first` function to a vector of strings, ensuring that it returns a vector of strings as well
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// Step 3. Apply the `capitalize_first` function again to a list, but try and ensure it returns a single string
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// As always, there are hints if you execute `rustlings hint iterators2`!
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// I AM NOT DONE
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pub fn capitalize_first(input: &str) -> String {
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let mut c = input.chars();
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match c.next() {
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None => String::new(),
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Some(first) => first.collect::<String>() + c.as_str(),
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}
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}
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#[cfg(test)]
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mod tests {
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use super::*;
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// Step 1.
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// Tests that verify your `capitalize_first` function implementation
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#[test]
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fn test_success() {
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assert_eq!(capitalize_first("hello"), "Hello");
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}
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#[test]
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fn test_empty() {
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assert_eq!(capitalize_first(""), "");
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}
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// Step 2.
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#[test]
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fn test_iterate_string_vec() {
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let words = vec!["hello", "world"];
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let capitalized_words: Vec<String> = // TODO
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assert_eq!(capitalized_words, ["Hello", "World"]);
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}
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#[test]
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fn test_iterate_into_string() {
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let words = vec!["hello", " ", "world"];
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let capitalized_words = // TODO
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assert_eq!(capitalized_words, "Hello World");
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}
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}
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