Format a String Without Printing in Golang

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Jay Singh Mar 17, 2022
Go Go String
Format a String Without Printing in Golang

The Printf is arguably the most common implementation of any variable formatted as a string. Golang has a simple technique of formatting a string without printing it.

The Sprintf() function of the fmt package in Go can be used to do this. The sole difference between Printf() & Sprintf() is Printf() formats and prints the message, whereas Sprintf() merely formats the message.

Use the Sprintf() Function to Format a String in Golang

The formatting functions format the string based on the format specifiers sent to them.

package main

import (
    "fmt"
)

func main() {
    name := "Jay"
    age := 23

    res := fmt.Sprintf("%s is %d years old", name, age)
    fmt.Println(res)
}

Output:

Jay is 23 years old

Another example is the sprintf() method in the fmt package formats a string and returns the output string.

package main

import (
    "fmt"
)

func main() {
    name := "Jay"
    country := "India"

    str := fmt.Sprintf("%s is from %s\n", name, country)

    fmt.Println(str)

    name = "Mike"
    age := 20

    str = fmt.Sprintf("%s is %d\n", name, age)

    fmt.Println(str)
}

Output:

Jay is from India

Mike is 20

This last example demonstrates how to rearrange the format specifiers.

package main

import (
    "fmt"
)

func main() {
    a := 2
    b := 3
    c := 4

    res := fmt.Sprintf("There are %d grapes, %d bananas, %d and strawberries.", a, b, c)
    fmt.Println(res)
}

Output:

There are 2 grapes, 3 bananas, 4 and strawberries

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