CODEWITHSUNDEEP
go
null
null

Reputation: 928

go - print without space between items

fmt.Println("a","b")

I want to print the two strings without space padding, namely "ab", but the above will print "a b".

Go fmt

Do I just switch to using Printf ?

fmt.Printf("%s%s\n","a","b")

Upvotes: 16

Views: 16311

Answers (5)

David Budworth
David Budworth

Reputation: 11626

Plain old print will work if you make the last element "\n".
It will also be easier to read if you aren't used to printf style formatting.

See here on play

fmt.Println("a","b")
fmt.Print("a","b","\n")
fmt.Printf("%s%s\n","a","b")

will print:

a b
ab
ab

Upvotes: 18

JessonChan
JessonChan

Reputation: 206

the solution in my project 

package main

import "fmt"

var formatMap = map[int]string{
    0: "",
    1: "%v",
}

func Println(v ...interface{}) {
    l := len(v)
    if s, isOk := formatMap[l]; !isOk {
        for i := 0; i < len(v); i++ {
            s += "%v"
        }
        formatMap[l] = s
    }
    s := formatMap[l] + "\n"
    fmt.Printf(s, v...)
}
func main() {
    Println()
    Println("a", "b")
    Println("a", "b")
    Println("a", "b", "c", 1)
}

Upvotes: -1

icecrime
icecrime

Reputation: 76765

You'd have to benchmark to compare performance, but I'd rather use the following than a Printf:

fmt.Println(strings.Join([]string{"a", "b"}, ""))

Remember to import "strings", and see strings.Join documentation for an explanation.

Upvotes: -1

Mateusz Dymczyk
Mateusz Dymczyk

Reputation: 15141

As it can be found in the doc:

Println formats using the default formats for its operands and writes to standard output. Spaces are always added between operands and a newline is appended. It returns the number of bytes written and any write error encountered.

So you either need to do what you already said or you can concatenate the strings before printing:

fmt.Println("a"+"b")

Depending on your usecase you can use strings.Join(myStrings, "") for that purpose.

Upvotes: 12

GHugo
GHugo

Reputation: 2654

Println relies on doPrint(args, true, true), where first argument is addspace and second is addnewline. So Prinln ith multiple arguments will always print space.

It seems there is no call of doPrint(args, false, true) which is what you want. Printf may be a solution, Print also but you should add a newline.

Upvotes: 2

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