How to check the specified rune in Golang String?
Last Updated :
12 Jul, 2025
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 the Go strings, you are allowed to check the given string contain the specified rune in it using
ContainsRune() function. This function returns true if the given string contains the specified rune in it, or this function returns false if the given string does not contain the specified rune. It is defined under the string package so, you have to import string package in your program for accessing ContainsRune function.
Syntax:
func ContainsRune(str string, r rune) bool
Here,
str is the string and
r is s rune. The return type of this function is bool. Let us discuss this concept with the help of the given examples:
Example 1:
C
// Go program to illustrate how to check
// the given string containing the rune
package main
import (
"fmt"
"strings"
)
func main() {
// Creating and initializing a string
// Using shorthand declaration
string_1 := "Welcome to GeeksforGeeks"
string_2 := "AppleAppleAppleAppleAppleApple"
string_3 := "%G%E%E%K%S"
// Creating and initializing rune
var r1, r2, r3 rune
r1 = 'R'
r2 = 'p'
r3 = 42
// Check the given string
// containing the rune
// Using ContainsRune function
res1 := strings.ContainsRune(string_1, r1)
res2 := strings.ContainsRune(string_2, r2)
res3 := strings.ContainsRune(string_3, r3)
// Display the results
fmt.Printf("String 1: %s , Rune 1: %q , Present or Not: %t",
string_1, r1, res1)
fmt.Printf("\nString 2: %s , Rune 2: %q , Present or Not: %t",
string_2, r2, res2)
fmt.Printf("\nString 3: %s , Rune 3: %q , Present or Not: %t",
string_3, r3, res3)
}
String 1: Welcome to GeeksforGeeks , Rune 1: 'R' , Present or Not: false
String 2: AppleAppleAppleAppleAppleApple , Rune 2: 'p' , Present or Not: true
String 3: %G%E%E%K%S , Rune 3: '*' , Present or Not: false
Example 2:
C
// Go program to illustrate how to check
// the given string containing the rune
package main
import (
"fmt"
"strings"
)
func main() {
// Creating and Checking the given
// rune present in the given string
// Using ContainsRune function
res1 := strings.ContainsRune("****Welcome, to,"+
" GeeksforGeeks****", 60)
res2 := strings.ContainsRune("Learning x how x to "+
"x trim x a x slice of bytes", 'r')
res3 := strings.ContainsRune("Geeks,for,Geeks, Geek", 'G')
// Display the results
fmt.Println("Final Result:")
fmt.Println("Result 1: ", res1)
fmt.Println("Result 2: ", res2)
fmt.Println("Result 3: ", res3)
}
Final Result:
Result 1: false
Result 2: true
Result 3: true
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