Learn how to compare strings in the golang

A string value is a sequence of bytes.

In the software developer’s life, comparing strings and sorting it is a day to day routine. In this tutorial, we will learn different ways to compare strings in the golang.

Using the Comparison operators

==    equal
!=    not equal
<     less
<=    less or equal
>     greater
>=    greater or equal

To check if strings are equal or not, you can use == or !=.

package main

import (
    "fmt"
)

func main() {

    str1 := "golang"
    str2 := "gopher"

    fmt.Println(str1 == str2)
    fmt.Println(str1 != str2)

}

Output

false
true

To check the Lexicographic Order of 2 strings, you can use <, <=, >, >=.

Lexicographic Order: This is dictionary order, except that all the uppercase letters preceed all the lowercase letters.
Example: Uppercase A comes first then the lowercase a.

package main

import (
    "fmt"
)

func main() {

    str1 := "apple"
    str2 := "banana"
    str3 := "Apple"

    fmt.Printf("%s < %s = %v\n", str1, str2, str1 < str2)
    fmt.Printf("%s <= %s = %v\n", str1, str2, str1 <= str2)
    fmt.Printf("%s > %s = %v\n", str1, str2, str1 > str2)
    fmt.Printf("%s >= %s = %v\n", str1, str2, str1 >= str2)
    fmt.Printf("%s < %s = %v\n", str1, str3, str1 < str3)
    fmt.Printf("%s > %s = %v\n", str1, str3, str1 > str3)
}

Output

apple < banana = true
apple <= banana = true
apple > banana = false
apple >= banana = false
apple < Apple = false
apple > Apple = true

Note: In Lexicographic Order, Apple comes before apple. ? != ?

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Using the Compare function

Compare returns an integer comparing two strings lexicographically.
The result will be

 0 if a == b
-1 if a < b
+1 if a > b

Example:

package main

import (
    "fmt"
    "strings"
)

func main() {
    fmt.Println(strings.Compare("a", "b"))
    fmt.Println(strings.Compare("a", "a"))
    fmt.Println(strings.Compare("b", "a"))
}

Output

-1
0
1

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