String Length
In Go language, we can find the length of the string using two functions: len() and RuneCountInString(). The UTF-8 package provides the RuneCountInString() function that takes a string as an argument and returns the total number of runes presented in it. The len() function is used to find the number of bytes in the string.
Example
package main
import(
"fmt"
"unicode/utf8"
)
func main(){
str:="Coding Ninjas"
// string length using len() function
len1:=len(str)
// string length using RuneCountInString() function
len2:=utf8.RuneCountInString(str)
// printing the length of the string
fmt.Println("string:", str)
fmt.Println("Length of the string using len() function:", len1)
fmt.Println("Length of the string using RuneCountInString() function:", len2)
}
Output
string: Coding Ninjas
Length of the string using len() function: 13
Length of the string using RuneCountInString() function: 13
String Concatenation
The process of adding multiple strings is known as string concatenation, and in Go, we can achieve that using the + operator.
Example
package main
import(
"fmt"
)
func main(){
str1:="Coding"
str2:="Ninjas"
fmt.Println("Concatenated string:", str1 + " " + str2)
}
Output
Concatenated string: Coding Ninjas
String Encoding and Unicode Code Points
The Unicode standard specifies a unique value for each character in all kinds of human languages. The basic unit in Unicode is not character. It is code point instead. For most code points, each of them corresponds to a character, but each consists of several code points for a few characters.
In Go language, rune values represent the code points. The rune is a built-in alias of type int32.
There are several encoding methods in applications to represent code points, such as UTF-8 encoding and UTF-16 encoding. These days, the most popular encoding method is UTF-8 encoding. In Go language, all string constants are viewed as UTF-8 encoded. Illegal UTF-8 encoded string constants will make compilation fail at compile time. However, Go runtime can not prevent some strings from being illegally UTF-8 encoded at run time.
In UTF-8 encoding, we may store each code point value as one or more bytes (up to four bytes). For example, each English code point (corresponds to one English character) is stored as one byte; however, each Chinese code point (corresponds to one Chinese character) is stored as three bytes.
String Functions in Go
The standard library's "strings" package provides many useful string-related functions. Here is a list of important Golang string functions given below:
Contains function
We can search a particular string/character within a string using Contains(). It returns output either true or false.
Syntax
func Contains(str, substr string) bool
Count function
We use this function to count the number of non-overlapping instances of a string/text/character in the string.
Syntax
func Count(str, sep string) int
HasPrefix function
We use this function to check whether string str begins with a specified string. It returns true if string str begins with pfx string. Otherwise, it returns false.
Syntax:
func HasPrefix(str, pfx string) bool
HasSuffix function
We use this function to check whether string str ends with a specified string. It returns true if string str ends with sffx string. Otherwise, it returns false.
Syntax:
func HasSuffix(str, sffx string) bool
Join function
We use this function to concatenate the elements of string Slice to create a single string. The separator string sep specifies what to put between each slice element in the resulting string.
Syntax:
func Join(stringSlice []string, sep string) string
Repeat function
We use this function to repeat a string a specified number of times and return a new string consisting of cnt copies of the string str. The cnt must be greater or equal to 0.
Syntax:
func Repeat(str string, cnt int) string
Replace function
We use this function to replace some characters with other characters in a string. Here in the below syntax n specifies the number of characters we want to replace in string. If n is less than 0, there is no limit on the number of replacements.
Syntax:
func Replace(str, old, new string, n int) string
Split function
We use this function to break a string into a slice. This function splits the str string into all substrings separated by sep and returns a slice of the substrings between those separators.
Syntax:
func Split(str string, sep string) []string
ToLower function
We use this function to convert all characters of the str string to lowercase.
Syntax:
func ToLower(str string) string
ToUpper function
We use this function to convert all characters of the str string to uppercase.
Syntax:
func ToUpper(str string) string
Here is a Go program to demonstrate the above functions.
Example
package main
import(
"fmt"
str "strings"
)
func main(){
fmt.Println("Contains function: ", str.Contains("ninjas", "nj"))
fmt.Println("Count function: ", str.Count("ninjas", "n"))
fmt.Println("HasPrefix function: ", str.HasPrefix("ninjas", "ni"))
fmt.Println("HasSuffix function: ", str.HasSuffix("ninjas", "ass"))
fmt.Println("Index function: ", str.Index("ninjas", "j"))
fmt.Println("Join function: ", str.Join([]string{"Coding", "Ninjas"}, "-"))
fmt.Println("Repeat function: ", str.Repeat("C", 4))
fmt.Println("Replace function: ", str.Replace("ninjas", "n", "N", 2))
fmt.Println("Split function: ", str.Split("H-E-L-L-O", "-"))
fmt.Println("ToLower function: ", str.ToLower("CODING"))
fmt.Println("ToUpper function: ", str.ToUpper("coding"))
}
Output
Contains function: true
Count function: 2
HasPrefix function: true
HasSuffix function: false
Index function: 3
Join function: Coding-Ninjas
Repeat function: CCCC
Replace function: NiNjas
Split function: [H E L L O]
ToLower function: coding
ToUpper function: CODING
FAQs
-
How do we concatenate strings in Golang?
Ans: The easiest way of concatenating two or more strings in the Go language is by using the + operator.
-
How can we format a string without printing it?
Ans: We can format a string without printing it using the fmt.Sprintf() function. It formats a string in the same way as fmt.Printf(), but returns the string instead of printing it.
-
What are string literals in Golang?
Ans: A string literal represents a string constant obtained from concatenating a sequence of characters. Go supports two styles of string literals: raw string literals and interpreted string literals.
Raw string literals are character sequences between back quotes, as in `hi`.
Interpreted string literals are character sequences between double quotes, as in "hello".
Key takeaways
In this article, We have extensively discussed the Strings in the Go programming language. We also discussed some string functions with the help of syntax and examples.
Check out this article - C++ String Concatenation
We hope that this blog has helped you enhance your knowledge regarding Go String and if you would like to learn more, check out our article on Go Loops. You can read other C language articles by clicking here. Do upvote our blog to help ninjas grow. Happy Coding!
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