Range

Beginner · Collections & Loops

for ... range iterates over arrays, slices, strings, maps, and channels. It yields index/value for slices and arrays, key/value for maps, and runes (with byte offsets) for strings. Use _ to ignore a part you don’t need.

Resources

• A Tour of Go: Range
• Go by Example: Range over Built-in Types

Exercises

range1 compile

Iterate a slice with range.

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Use the `range` keyword to iterate over collections like arrays, slices, and maps.

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range2 compile

Iterate a map’s keys and values with range.

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Use the `range` keyword to iterate over map values. Unlike arrays and slices, maps are iterated over by keys and values.

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range3 test

Use range to collect the even numbers.

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Use a `for` loop with `range` to check if each number is even and append it to the `evenNumbers` slice.

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