How to Split a String in Golang?

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:  []

My Personal Notes

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