Basic String Functions

This is a simple example of the implementation of some basic functions using the strings package. The unicode package is used for the example using runes.

If building a file, ensure to have the correct imports and package name:

package stringexamples

import (
    "strings"
    "unicode"
)
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...and for testing:

package stringexamples

import (
    "testing"
)
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Compare

// Test module
func TestStringsCompare(t *testing.T) {
    a := "Hello, World!"
    b := "Hello, World!"
    if CompareStrings(a, b) != 0 {
        t.Fatalf("Expected 0")
    }

    a = "Hello, World!"
    b = "Hello, Worl!"
    if CompareStrings(a, b) != 1 {
        t.Fatalf("Expected 1")
    }

    a = "Hello, World!"
    b = "Hello, World!!"
    if CompareStrings(a, b) != -1 {
        t.Fatalf("Expected -1")
    }
}

// CompareStrings compares two string values and returns an int
func CompareStrings(a string, b string) int {
    return strings.Compare(a, b)
}
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Contains

// Test module
func TestContainsString(t *testing.T) {
    a := "Hello, World!"
    b := "Hello, World"
    if ContainsString(a, b) != true {
        t.Fatalf("Expected true")
    }

    a = "Hello, World!"
    b = "Hway"
    if ContainsString(a, b) != false {
        t.Fatalf("Expected false")
    }
}

// ContainsString checks if string contains substr
func ContainsString(s string, substr string) bool {
    return strings.Contains(s, substr)
}
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Join

// Test module
func TestJoinString(t *testing.T) {
    a := []string{"Hello", "World!"}
    b := "Hello, World!"

    res := JoinString(a, ", ")

    if res != b {
        t.Fatalf("Expected %s but got %s", b, res)
    }
}

// JoinString turns a string slice into a string
func JoinString(str []string, de string) string {
    return strings.Join(str, de)
}
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Split

// Test module
func TestSplitString(t *testing.T) {
    a := "Hello World!"
    b := []string{"Hello", "World!"}

    res := SplitString(a, " ")

    for i, v := range res {
        if v != b[i] {
            t.Fatalf("Expected string %s but got %s", v, b[i])
        }
    }
}

// SplitString turns a string in a []string with delimiter
func SplitString(str string, de string) []string {
    return strings.Split(str, de)
}
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Lower case a string using Map

// Test module
func TestMapToLowerString(t *testing.T) {
    a := "Hello, World!"
    b := "hello, world!"

    res := MapOverStringToLower(a)

    if res != b {
        t.Fatalf("Expected %s but got %s", b, res)
    }
}

// MapOverStringToLower uses map to lower case a string
func MapOverStringToLower(str string) string {
    toLower := func(r rune) rune {
        return unicode.ToLower(r)
    }

    return strings.Map(toLower, str)
}
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