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Golang strings Package Functions
In Go language, the strings package is used for various string-related operations, strings package has a variety of functions to manipulate UTF-8 encoded strings. To use these string functions – we need to import the strings package.
List of Golang strings Package Functions
| Function |
Description |
| strings.Compare() |
It returns 0 if both strings are the same, -1 if the first string is less than the second string, and +1 if the first string is greater than the second string. |
| strings.Contains() |
It checks whether a substring is within the string. It returns true if the string contains the substring, false otherwise. |
| strings.ContainsRune() |
It checks whether a Unicode code point is within the string. It returns true if the string contains the Unicode code point, false otherwise. |
| strings.Count() |
It counts and returns the number of non-overlapping instances of substring in the string. If the substring is empty, it returns the number of Unicode code points in string +1. |
| strings.EqualFold() |
It checks whether the given strings (UTF-8 strings) are equal under Unicode case-folding (i.e., case-insensitive). |
| strings.Fields() |
It returns a slice of substrings if the string is there, otherwise, it returns an empty slice if the string contains only white spaces. |
| strings.FieldsFunc() |
It returns a slice of substrings if the function satisfies the condition applied on all code points of the string. If the string is empty, it returns an empty slice. |
| strings.HasPrefix() |
It returns true if the string begins with a prefix, false otherwise. |
| strings.HasSuffix() |
It returns true if the string ends with suffix, false otherwise. |
| strings.Index() |
It returns the index of the first occurrence (instance) of a substring in a string, or -1 if the substring is not present in the string. |
| strings.IndexAny() |
It returns the index of the first occurrence (instance) of any Unicode code point from substring in the string, or -1 if no Unicode code point from substring is present in the string. |
| strings.IndexByte() |
It gets the index of the first occurrence (instance) of a character (byte) in the string and returns the index, or -1 if the byte is not present in the string. |
| strings.IndexFunc() |
It gets the index of the first Unicode code point satisfying the function with respect to the character of the string. It returns the index, or -1 if any character of the string does not satisfy the function. |
| strings.IndexRune() |
It gets the index of the first occurrence (instance) of the Unicode code point (a rune type). It returns the index of the first instance of the character in the string, -1 otherwise. |
| strings.Join() |
It joins (concatenates) the slices of strings (elements of the first parameter) with the given separator to create a single string. It returns a concatenated string with the separator. |
| strings.LastIndex() |
It returns the index of the last occurrence (instance) of the substring in a string, or -1 if the substring is not present in the string. |
| strings.LastIndexAny() |
It returns the index of the last occurrence (instance) of any Unicode code point from substring in the string, or -1 if no Unicode code point from substring is present in the string. |
| strings.LastIndexByte() |
It returns the index of the last occurrence (instance) of character (byte) in the string, or -1 if the character (byte) is not present in the string. |
| strings.LastIndexFunc() |
It gets the index of the last Unicode code point satisfying the function with respect to the character of the string. It returns the index, or -1 if any character of the string does not satisfy the function. |
| strings.Map() |
It returns a copy of the given string with all its characters modified according to the mapping function. |
| strings.Repeat() |
It creates and returns a string consisting of count copies of the given string. |
| strings.Replace() |
It creates and returns a copy of the string with the first n non-overlapping occurrences (instances) of the old substring replaced by a new substring. |
| strings.Split() |
It splits the given string (slice) into all substrings separated by the given separator and returns a slice of the substrings between those separators. |
| strings.SplitAfter() |
It splits the given string (slice) into all substrings after each instance of the given separator and returns a slice of those substrings. |
| strings.SplitN() |
It splits the given string (slice) into all substrings by the given separator and returns a slice of the N substrings between those separators. |
| strings.Title() |
It returns a copy of the given string with all Unicode letters that begin words mapped to their Unicode title case. |
| strings.ToLower() |
It returns a copy of the string with all Unicode letters mapped to their lower case. |
| strings.ToLowerSpecial() |
It returns a copy of the string with all Unicode letters mapped to their lower case using the case mapping specified by unicode.SpecialCase type. |
| strings.ToUpper() |
It returns a copy of the string with all Unicode letters mapped to their upper case. |
| strings.ToUpperSpecial() |
It returns a copy of the string with all Unicode letters mapped to their upper case using the case mapping specified by unicode.SpecialCase type. |
| strings.ToValidUTF8() |
It returns a copy of the string with each run of invalid UTF-8 byte sequences replaced by the replacement string. |
| strings.Trim() |
It returns a string with all specified leading and trailing Unicode code points removed. |
| strings.TrimFunc() |
It returns a string with all leading and trailing Unicode code points c satisfying f(c) removed. |
| strings.TrimLeft() |
It returns a string with all specified leading Unicode code points removed. |
| strings.TrimLeftFunc() |
It returns a string with all leading Unicode code points c satisfying f(c) removed. |
| strings.TrimPrefix() |
It returns a string without the provided leading prefix string. |
| strings.TrimRight() |
It returns a string with all specified trailing Unicode code points removed. |
| strings.TrimRightFunc() |
It returns a string with all trailing Unicode code points c satisfying f(c) removed. |
| strings.TrimSpace() |
It returns a string with all leading and trailing white space removed, as defined by Unicode. |
| strings.TrimSuffix() |
It returns a string without the provided leading suffix string. |
Example of strings.Compare()
// Golang program to demonstrate the
// example of strings.Compare() Function
package main
import (
"fmt"
"strings"
)
func main() {
fmt.Println(strings.Compare("abc", "abc"))
fmt.Println(strings.Compare("abc", "abd"))
fmt.Println(strings.Compare("xyz", "pqr"))
}
Output:
0
-1
1
Example of strings.Contains()
// Golang program to demonstrate the
// example of strings.Contains() Function
package main
import (
"fmt"
"strings"
)
func main() {
fmt.Println(strings.Contains("Hello, world!", "Hello"))
fmt.Println(strings.Contains("Hello, world!", "world"))
fmt.Println(strings.Contains("Hello, world!", "Hi"))
}
Output:
true
true
false
Example of strings.ContainsRune()
// Golang program to demonstrate the
// example of strings.ContainsRune() Function
package main
import (
"fmt"
"strings"
)
func main() {
// 72 is the Unicode code point value for 'H' (Uppercase)
// 119 is the Unicode code point value for 'w' (Lowercase)
// 97 is the Unicode code point value for 'a' (Lowercase)
fmt.Println(strings.ContainsRune("Hello, world!", 72))
fmt.Println(strings.ContainsRune("Hello, world!", 119))
fmt.Println(strings.ContainsRune("Hello, world!", 97))
}
Output:
true
true
false
Example strings.Count()
// Golang program to demonstrate the
// example of strings.Count() Function
package main
import (
"fmt"
"strings"
)
func main() {
fmt.Println(strings.Count("Hello, world!", "o"))
fmt.Println(strings.Count("Hello, world!", "l"))
fmt.Println(strings.Count("Hello, world!", "Hi"))
fmt.Println(strings.Count("Hi guys, she said Hi to everyone.", "Hi"))
fmt.Println(strings.Count("Hello, world!", ""))
}
Output:
2
3
0
2
14
Example of strings.EqualFold()
// Golang program to demonstrate the
// example of strings.EqualFold() Function
package main
import (
"fmt"
"strings"
)
func main() {
fmt.Println(strings.EqualFold("Hello", "hello"))
fmt.Println(strings.EqualFold("HELLO, WORLD!", "Hello, world!"))
fmt.Println(strings.EqualFold("Hello There?", "Hi There?"))
}
Output:
true
true
false