How to Return a String from the Function in Golang?

In programming, to make the code more modular, usable, and readable we break the code into different small blocks and these blocks are known as functions. A string is a data structure consisting of a set of alphabets. In solving any programming problem we want that the function should return some set of alphabets then we create a string in the function that the function returns in the end.

This tutorial will explain this concept with the help of two examples.

• In the first example, we will define two strings and create a function that will return the string that is larger in length;

• in the second example, we will create a function in which we will reverse the string and return it at the end of the function.

Method 1

Algorithm

• Step 1: var stringVariable1, stringVariable2 string − Declare the string variables.

• Step 2: stringVariable1 = "tutorialpoints" stringVariable2 = "tutorial" − Initialize the string variables.

• longerStringVariable := longerString(stringVariable1, stringVariable2) − Calling the function with two parameters that will return the longer string and storing it into a variable.

• if len(stringVariable1) >= len(stringVariable2) { } − Comparing both the strings passed in the parameter using len() function and returning the first string if it is longer.

• else {} − returning the second string in the else condition.

• Print the longer string at the end of the function.

Example

In this example, we are going to return the string that is larger in length. To achieve this we will use the len() function that returns the length of the variable that is passed in the function.

package main

import (
    // fmt package provides the function to print anything
    "fmt"
)

// golang function with string parameter and string return type
func longerString(stringVariable1, stringVariable2 string) string {
    //Comparing the length of both the strings
    if len(stringVariable1) >= len(stringVariable2) {
        // returning first string if it longer
        return stringVariable1
    } else {
        // returning second string if it longer
        return stringVariable2
    }
}

func main() {
    // declaring the string
    var stringVariable1, stringVariable2 string

    //Initializing the string
    stringVariable1 = "tutorialpoints"
    stringVariable2 = "tutorial"

    fmt.Println("Golang program to return a string from the function.")

    // passing argument in the function and storing the longer string in a variable
    longerStringVariable := longerString(stringVariable1, stringVariable2)

    fmt.Println("The longer string is", longerStringVariable)

}

Output

Golang program to return a string from the function.
The longer string is tutorialpoints

Algorithm

• Step 1: var stringVariable string − Declare the string variable.

• Step 2: string = "tutorialpoints" − Initialize the string variable.

• Step 3: reverseStringVariable := reverseString(stringVariable) − Calling a function to reverse the string by passing a string variable to it and storing it into a variable.

• runeArray := []rune(stringVariable) − Creating a rune from the string passed in the parameter.

• ○ for i := 0; i < len(stringVariable)/2; i++ {} − Running a for loop till half of the length of the string.

• runeArray[i], runeArray[len(stringVariable)−i−1] = runeArray[len(stringVariable)−i−1], runeArray[i] − the concept we are using here is that we swapped the ith element with the len − i index element.

• Returning the rune by converting it into the string.

• Printing the reversed array.

Example

In this example, we will reverse the string using a for loop and return it at the end of the function.

package main

import (
    // fmt package provides the function to print anything
    "fmt"
)

// golang function with string parameter and string return type
func reverseString(stringVariable string) string {
    //Creating a rune from the string
    runeArray := []rune(stringVariable)

    // running a for loop over the rune from 0 till half
    // of the length of the string
    for i := 0; i < len(stringVariable)/2; i++ {
        // swapping the ith and len - i element
        runeArray[i], runeArray[len(stringVariable)-i-1] = runeArray[len(stringVariable)-i-1], runeArray[i]
    }

    return string(runeArray)
}

func main() {
    // declaring the string
    var stringVariable string

    // initializing the string
    stringVariable = "tutorialpoints"

    fmt.Println("Golang program to return a string from the function.")

    // passing argument in the function and storing the reversed string in a variable
    reverseStringVariable := reverseString(stringVariable)

    fmt.Println("The reversed string of", stringVariable, "is", reverseStringVariable)

}

Output

Golang program to return a string from the function.
The reversed string of tutorialpoints is stnioplairotut

Conclusion

These are the two examples of returning the string from a function where in the first example we have returned the string that is longer in length and in the second example we have returned the reverse of the string passed in the parameter. To learn more about go you can explore these tutorials.