How do you write multiline strings in Go?
StringGoMultilineString Problem Overview
Does Go have anything similar to Python's multiline strings:
"""line 1
line 2
line 3"""
If not, what is the preferred way of writing strings spanning multiple lines?
String Solutions
Solution 1 - String
According to the language specification, you can use a raw string literal, where the string is delimited by backticks instead of double quotes.
`line 1
line 2
line 3`
Solution 2 - String
You can write:
"line 1" +
"line 2" +
"line 3"
which is the same as:
"line 1line 2line 3"
Unlike using back ticks, it will preserve escape characters. Note that the "+" must be on the 'leading' line - for instance, the following will generate an error:
"line 1"
+"line 2"
Solution 3 - String
Use raw string literals for multi-line strings:
func main(){
multiline := `line
by line
and line
after line`
}
Raw string literals
> Raw string literals are character sequences between back quotes, as in `foo`
. Within the quotes, any character may appear except back quote.
A significant part is that is raw literal not just multi-line and to be multi-line is not the only purpose of it.
> The value of a raw string literal is the string composed of the uninterpreted (implicitly UTF-8-encoded) characters between the quotes; in particular, backslashes have no special meaning...
So escapes will not be interpreted and new lines between ticks will be real new lines.
func main(){
multiline := `line
by line \n
and line \n
after line`
// \n will be just printed.
// But new lines are there too.
fmt.Print(multiline)
}
Concatenation
Possibly you have long line which you want to break and you don't need new lines in it. In this case you could use string concatenation.
func main(){
multiline := "line " +
"by line " +
"and line " +
"after line"
fmt.Print(multiline) // No new lines here
}
Since " " is interpreted string literal escapes will be interpreted.
func main(){
multiline := "line " +
"by line \n" +
"and line \n" +
"after line"
fmt.Print(multiline) // New lines as interpreted \n
}
Solution 4 - String
From String literals:
- raw string literal supports multiline (but escaped characters aren't interpreted)
- interpreted string literal interpret escaped characters, like '
\n
'.
But, if your multi-line string has to include a backquote (`), then you will have to use an interpreted string literal:
`line one
line two ` +
"`" + `line three
line four`
You cannot directly put a backquote (`) in a raw string literal (`xx
`).
You have to use (as explained in "how to put a backquote in a backquoted string?"):
+ "`" + ...
Solution 5 - String
Go and multiline strings
Using back ticks you can have multiline strings:
package main
import "fmt"
func main() {
message := `This is a
Multi-line Text String
Because it uses the raw-string back ticks
instead of quotes.
`
fmt.Printf("%s", message)
}
Instead of using either the double quote (“) or single quote symbols (‘), instead use back-ticks to define the start and end of the string. You can then wrap it across lines.
> If you indent the string though, remember that the white space will > count.
Please check the playground and do experiments with it.
Solution 6 - String
Creating a multiline string in Go is actually incredibly easy. Simply use the backtick (`) character when declaring or assigning your string value.
package main
import (
"fmt"
)
func main() {
// String in multiple lines
str := `This is a
multiline
string.`
fmt.Println(str + "\n")
// String in multiple lines with tab
tabs := `This string
will have
tabs in it`
fmt.Println(tabs)
}
Solution 7 - String
You can put content with `` around it, like
var hi = `I am here,
hello,
`
Solution 8 - String
You have to be very careful on formatting and line spacing in go, everything counts and here is a working sample, try it https://play.golang.org/p/c0zeXKYlmF
package main
import "fmt"
func main() {
testLine := `This is a test line 1
This is a test line 2`
fmt.Println(testLine)
}
Solution 9 - String
you can use raw literals. Example
s:=`stack
overflow`
Solution 10 - String
For me, I need to use ` grave accent/backquote and just write a simple test
+ "`" + ...
is ugly and inconvenient
so I take a characterfor example: U+1F42C to replace it
a demo
myLongData := `line1
line2 🐬aaa🐬
line3
` // maybe you can use IDE to help you replace all ` to 🐬
myLongData = strings.ReplaceAll(myLongData, "🐬", "`")
Performance and Memory Evaluation
+ "`"
v.s. replaceAll(, "", "`")
package main
import (
"strings"
"testing"
)
func multilineNeedGraveWithReplaceAll() string {
return strings.ReplaceAll(`line1
line2
line3 🐬aaa🐬`, "🐬", "`")
}
func multilineNeedGraveWithPlus() string {
return `line1
line2
line3` + "`" + "aaa" + "`"
}
func BenchmarkMultilineWithReplaceAll(b *testing.B) {
for i := 0; i < b.N; i++ {
multilineNeedGraveWithReplaceAll()
}
}
func BenchmarkMultilineWithPlus(b *testing.B) {
for i := 0; i < b.N; i++ {
multilineNeedGraveWithPlus()
}
}
cmd
> go test -v -bench=. -run=none -benchmem
see more testing.B
output
goos: windows
goarch: amd64
pkg: tutorial/test
cpu: Intel(R) Core(TM) i7-6700 CPU @ 3.40GHz
BenchmarkMultilineWithReplaceAll
BenchmarkMultilineWithReplaceAll-8 12572316 89.95 ns/op 24 B/op 1 allocs/op
BenchmarkMultilineWithPlus
BenchmarkMultilineWithPlus-8 1000000000 0.2771 ns/op 0 B/op 0 allocs/op
PASS
ok tutorial/test 7.566s
Yes, The + "`"
has a better performance than the other.
Solution 11 - String
For me this is what I use if adding \n
is not a problem.
fmt.Sprintf("Hello World\nHow are you doing today\nHope all is well with your go\nAnd code")
Else you can use the raw string
multiline := `Hello Brothers and sisters of the Code
The grail needs us.
`