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Golang strconv.Atoi() Function with Examples

Golang | strconv.Atoi() Function: Here, we are going to learn about the Atoi() function of the strconv package with its usages, syntax, and examples.
Submitted by IncludeHelp, on September 06, 2021

strconv.Atoi()

The Atoi() function is an inbuilt function of the strconv package which is used to convert (interpret) a given string s in the given base (10) and bit size (0) and returns the corresponding integer value. The Atoi() function is equivalent to ParseInt(s, 10, 0), converted to type int.

It accepts one parameter (s string) and returns the corresponding integer value, error (if any).

Syntax:

func Atoi(s string) (int, error)

Parameter(s):

• s : A string value that is to be converted into an integer value.

Return Value:

The return type of Atoi() function is (int, error), it returns the corresponding integer value, error (if any).

Example 1:

// Golang program to demonstrate the
// example of strconv.Atoi() Function

package main

import (
	"fmt"
	"strconv"
)

func main() {
	// Converting string having
	// base-10 integer value to integer
	fmt.Println(strconv.Atoi("10"))
	fmt.Println(strconv.Atoi("-10"))
	fmt.Println(strconv.Atoi("56789"))
	fmt.Println(strconv.Atoi("-1234"))

	// Converting string having
	// base-16 integer value to integer
	// This conversion will generate an error
	fmt.Println(strconv.Atoi("ff"))
	fmt.Println(strconv.Atoi("123ab6"))
}

Output:

10 <nil>
-10 <nil>
56789 <nil>
-1234 <nil>
0 strconv.Atoi: parsing "ff": invalid syntax
0 strconv.Atoi: parsing "123ab6": invalid syntax

Example 2:

// Golang program to demonstrate the
// example of strconv.Atoi() Function

package main

import (
	"fmt"
	"strconv"
)

func main() {
	var x string
	var result int
	var err error

	x = "108"
	result, err = strconv.Atoi(x)
	fmt.Println("x:", x)
	if err == nil {
		fmt.Println("Conversion successful, result:", result)
	} else {
		fmt.Println("Conversion failed, result:", result)
		fmt.Println("Error:", err)
	}

	x = "-15"
	result, err = strconv.Atoi(x)
	fmt.Println("x:", x)
	if err == nil {
		fmt.Println("Conversion successful, result:", result)
	} else {
		fmt.Println("Conversion failed, result:", result)
		fmt.Println("Error:", err)
	}

	x = "108ffc"
	result, err = strconv.Atoi(x)
	fmt.Println("x:", x)
	if err == nil {
		fmt.Println("Conversion successful, result:", result)
	} else {
		fmt.Println("Conversion failed, result:", result)
		fmt.Println("Error:", err)
	}
}

Output:

x: 108
Conversion successful, result: 108
x: -15
Conversion successful, result: -15
x: 108ffc
Conversion failed, result: 0
Error: strconv.Atoi: parsing "108ffc": invalid syntax

Example 3:

// Golang program to demonstrate the
// example of strconv.Atoi() Function

package main

import (
	"fmt"
	"strconv"
)

func main() {
	x := "108"
	if result, err := strconv.Atoi(x); err == nil {
		fmt.Printf("Type(%T), Value(%v)\n", result, result)
	}

	x = "-12345"
	if result, err := strconv.Atoi(x); err == nil {
		fmt.Printf("Type(%T), Value(%v)\n", result, result)
	}

	x = "ff"
	if result, err := strconv.Atoi(x); err == nil {
		fmt.Printf("Type(%T), Value(%v)\n", result, result)
	}
}

Output:

Type(int), Value(108)
Type(int), Value(-12345)

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