String equals

Go strings may have the same rune content, and this is important for us to detect. The strings may have been created in different ways.

In Go we use the equality operator to test the contents of strings. This is case-sensitive. Strings.EqualFold can be used for case insensitivity.

String equals example

Here we create 2 strings that end up having the same values ("catcat"). They are not the same string, but their contents are identical.

package main

import (
    "fmt"
    "strings"
)

func main() {
    // Create 2 equal strings in different ways.
    test1 := "catcat"
    test2 := strings.Repeat("cat", 2)

    // Display the strings.
    fmt.Println("test1:", test1)
    fmt.Println("test2:", test2)

    // Test the strings for equality.
    if test1 == test2 {
        fmt.Println("Strings are equal")
    }

    if test1 != test2 {
        fmt.Println("Not reached")
    }
}
test1: catcat
test2: catcat
Strings are equal

EqualFold

Uppercase letters are not equal to lowercase letters. But with EqualFold we fold cases. This makes "A" equal to "a." No string copies or conversions are required.

package main

import (
    "fmt"
    "strings"
)

func main() {
    value1 := "cat"
    value2 := "CAT"

    // This returns true because cases are ignored.
    if strings.EqualFold(value1, value2) {
        fmt.Println(true)
    }
}
true

With the equals-sign operator and strings.EqualFold, we can compare strings. Case-insensitivity is not always needed. Using the equals operator is best when it is sufficient.