Trying to interpolate an int value into a string using %v formatter as follows, yet nothing is printed,
package main
import "fmt"
func inc(i int) int {
return i + 1
}
func main() {
fmt.Sprintln("inc 1 equal %v", inc(1))
}
How to interpolate an int value ?
3 Answers
fmt.Sprintln returns a String, but doesn't print anything. (The name was taken from the also confusingly named C function sprintf.)
What you need is Printf, but you have to add the newline yourself:
fmt.Printf("inc 1 equal %v\n", inc(1))
Sprintln formats using the default formats for its operands and returns the resulting string. Spaces are always added between operands and a newline is appended.
Sprint format a string and returns such a string, it does write nothing. What you're searching for is Print
Furthermore, the variant ln doesn't parse %, it only add the new line character at the end of the string.
So, if you want to write to standard output using format, you should use this:
fmt.Printf("inc 1 equal %v", inc(1))
