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| -rw-r--r-- | src/doc/tutorial.md | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/src/doc/tutorial.md b/src/doc/tutorial.md index 094771897f4..6ae8c1d704d 100644 --- a/src/doc/tutorial.md +++ b/src/doc/tutorial.md @@ -582,6 +582,32 @@ loop { This code prints out a weird sequence of numbers and stops as soon as it finds one that can be divided by five. +There is also a for-loop that can be used to iterate over a range of numbers: + +~~~~ +for n in range(0, 5) { + println!("{}", n); +} +~~~~ + +The snippet above prints integer numbers under 5 starting at 0. + +More generally, a for loop works with anything implementing the `Iterator` trait. +Data structures can provide one or more methods that return iterators over +their contents. For example, strings support iteration over their contents in +various ways: + +~~~~ +let s = "Hello"; +for c in s.chars() { + println!("{}", c); +} +~~~~ + +The snippet above prints the characters in "Hello" vertically, adding a new +line after each character. + + # Data structures ## Structs |