How to merge multiple strings and int into a single string

You can use strings.Join, which is almost 3x faster than fmt.Sprintf. However it can be less readable.

output := strings.Join([]string{"key:", "value", ", key2:", strconv.Itoa(100)}, "")

See https://play.golang.org/p/AqiLz3oRVq

strings.Join vs fmt.Sprintf

BenchmarkFmt-4       2000000           685 ns/op
BenchmarkJoins-4     5000000           244 ns/op

Buffer

If you need to merge a lot of strings, I'd consider using a buffer rather than those solutions mentioned above.

I like to use fmt's Sprintf method for this type of thing. It works like Printf in Go or C only it returns a string. Here's an example:

output := fmt.Sprintf("%s%s%s%d", "key:", "value", ", key2:", 100)

Go docs for fmt.Sprintf

You can simply do this:

package main

    import (
        "fmt" 
        "strconv"
    )
    
    func main() {

         
         result:="str1"+"str2"+strconv.Itoa(123)+"str3"+strconv.Itoa(12)
         fmt.Println(result)
         
    }

Using fmt.Sprintf()

var s1="abc"
var s2="def"
var num =100
ans:=fmt.Sprintf("%s%d%s", s1,num,s2);
fmt.Println(ans);