How to Split a String in Golang?

Last Updated : 26 Aug, 2019

In Go language, strings are different from other languages like Java, C++, Python, etc. It is a sequence of variable-width characters where each and every character is represented by one or more bytes using UTF-8 Encoding. In Go strings, you are allowed to split a string into a slice with the help of following functions. These functions are defined under strings package so, you have to import strings package in your program for accessing these functions:

1. Split: This function splits a string into all substrings separated by the given separator and returns a slice which contains these substrings.

Syntax:

func Split(str, sep string) []string

Here, str is the string and sep is the separator. If str does not contain the given sep and sep is non-empty, then it will return a slice of length 1 which contain only str. Or if the sep is empty, then it will split after each UTF-8 sequence. Or if both str and sep are empty, then it will return an empty slice.

Example:

// Go program to illustrate how to split a string
package main
  
import (
    "fmt"
    "strings"
)
  
// Main function
func main() {
  
    // Creating and initializing the strings
    str1 := "Welcome, to the, online portal, of GeeksforGeeks"
    str2 := "My dog name is Dollar"
    str3 := "I like to play Ludo"
  
    // Displaying strings
    fmt.Println("String 1: ", str1)
    fmt.Println("String 2: ", str2)
    fmt.Println("String 3: ", str3)
  
    // Splitting the given strings
    // Using Split() function
    res1 := strings.Split(str1, ",")
    res2 := strings.Split(str2, "")
    res3 := strings.Split(str3, "!")
    res4 := strings.Split("", "GeeksforGeeks, geeks")
  
    // Displaying the result
  
    fmt.Println("\nResult 1: ", res1)
    fmt.Println("Result 2: ", res2)
    fmt.Println("Result 3: ", res3)
    fmt.Println("Result 4: ", res4)
  
}

Output:

String 1:  Welcome, to the, online portal, of GeeksforGeeks
String 2:  My dog name is Dollar
String 3:  I like to play Ludo

Result 1:  [Welcome  to the  online portal  of GeeksforGeeks]
Result 2:  [M y   d o g   n a m e   i s   N a w a b]
Result 3:  [I like to play Ludo]
Result 4:  []

2. SplitAfter: This function splits a string into all substrings after each instance of the given separator and returns a slice which contains these substrings.

Syntax:

func SplitAfter(str, sep string) []string

Example:

// Go program to illustrate how to split a string
package main
  
import (
    "fmt"
    "strings"
)
  
// Main function
func main() {
  
    // Creating and initializing the strings
    str1 := "Welcome, to the, online portal, of GeeksforGeeks"
    str2 := "My dog name is Dollar"
    str3 := "I like to play Ludo"
  
    // Displaying strings
    fmt.Println("String 1: ", str1)
    fmt.Println("String 2: ", str2)
    fmt.Println("String 3: ", str3)
  
    // Splitting the given strings
    // Using SplitAfter() function
    res1 := strings.SplitAfter(str1, ",")
    res2 := strings.SplitAfter(str2, "")
    res3 := strings.SplitAfter(str3, "!")
    res4 := strings.SplitAfter("", "GeeksforGeeks, geeks")
  
    // Displaying the result
    fmt.Println("\nResult 1: ", res1)
    fmt.Println("Result 2: ", res2)
    fmt.Println("Result 3: ", res3)
    fmt.Println("Result 4: ", res4)
  
}

Output:

String 1:  Welcome, to the, online portal, of GeeksforGeeks
String 2:  My dog name is Dollar
String 3:  I like to play Ludo

Result 1:  [Welcome,  to the,  online portal,  of GeeksforGeeks]
Result 2:  [M y   d o g   n a m e   i s   N a w a b]
Result 3:  [I like to play Ludo]
Result 4:  []

3. SplitAfterN: This function splits a string into all substrings after each instance of the given separator and returns a slice which contains these substrings.

Syntax:

func SplitAfterN(str, sep string, m int) []string

Here, str is the string, sep is the separator, and m is used to find the number of substrings to return. Here, if m>0, then it returns at most m substrings and the last string substring will not split. If m == 0, then it will return nil. If m<0, then it will return all substrings.

Example:

// Go program to illustrate how to split a string
package main
  
import (
    "fmt"
    "strings"
)
  
// Main function
func main() {
  
    // Creating and initializing the strings
    str1 := "Welcome, to the, online portal, of GeeksforGeeks"
    str2 := "My dog name is Dollar"
    str3 := "I like to play Ludo"
  
    // Displaying strings
    fmt.Println("String 1: ", str1)
    fmt.Println("String 2: ", str2)
    fmt.Println("String 3: ", str3)
  
    // Splitting the given strings
    // Using SplitAfterN() function
    res1 := strings.SplitAfterN(str1, ",", 2)
    res2 := strings.SplitAfterN(str2, "", 4)
    res3 := strings.SplitAfterN(str3, "!", 1)
    res4 := strings.SplitAfterN("", "GeeksforGeeks, geeks", 3)
  
    // Displaying the result
    fmt.Println("\nResult 1: ", res1)
    fmt.Println("Result 2: ", res2)
    fmt.Println("Result 3: ", res3)
    fmt.Println("Result 4: ", res4)
  
}

Output:

String 1:  Welcome, to the, online portal, of GeeksforGeeks
String 2:  My dog name is Dollar
String 3:  I like to play Ludo

Result 1:  [Welcome,  to the, online portal, of GeeksforGeeks]
Result 2:  [M y   dog name is Dollar]
Result 3:  [I like to play Ludo]
Result 4:  []

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