Unexpected values in range loop
yourbasic.org/golang
Why does this code
primes := []int{2, 3, 5, 7}
for p := range primes {
fmt.Println(p)
}0
1
2
3
Answer
For arrays and slices, the range loop generates two values:
- first the index,
- then the data at this position.
If you omit the second value, you get only the indices.
To print the data, use the second value instead:
primes := []int{2, 3, 5, 7}
for _, p := range primes {
fmt.Println(p)
}
In this case, the blank identifier (underscore) is used for the return value you're not interested in.
See 4 basic range loop (for-each) patterns for all about range loops in Go.
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