GoLang String

FAQ

1. How do you concatenate strings in Go?

You can concatenate strings using the + operator.

fmt.Println("Hello, " + "World!")

2. How do you find the length of a string in Go?

Use the len function to get the length of a string.

message := "Hello World!"
fmt.Println("Length:", len(message)) // Length: 12

3. How do you extract a substring in Go?

Use slice notation to extract substrings.

message := "Hello World!"
fmt.Println("Substring:", message[0:5]) // "Hello"

4. How do you compare two strings in Go?

You can use == and != operators or the strings.Compare function.

msg1 := "one"
msg2 := "two"
fmt.Println("Equal?", msg1 == msg2)
fmt.Println("Not Equal?", msg1 != msg2)
 
fmt.Println(strings.Compare(msg1, msg2))

5. How do you check if a string contains a substring?

Use the strings.Contains function.

message := "Hello World!"
fmt.Println(strings.Contains(message, "World")) // true

6. How do you convert a string to uppercase or lowercase?

Use strings.ToUpper and strings.ToLower functions.

message := "Hello World!"
fmt.Println(strings.ToUpper(message)) // "HELLO WORLD!"
fmt.Println(strings.ToLower(message)) // "hello world!"

7. How do you split a string into substrings?

Use the strings.Split function.

message := "Hello World!"
fmt.Println(strings.Split(message, " ")) // ["Hello", "World!"]

8. How do you replace a substring in a string?

Use the strings.Replace function.

message := "Hello World!"
fmt.Println(strings.Replace(message, "World", "Go", 1)) // "Hello Go!"

9. How do you trim spaces from a string?

Use the strings.TrimSpace function.

message := "  Hello World!  "
fmt.Println(strings.TrimSpace(message)) // "Hello World!"

10. How do you get the first character of a string?

Use indexing to access the first character.

message := "Hello World!"
fmt.Printf("First character: %c\n", message[0])

Additional String Functions

Contains

Check if a string contains a substring.

fmt.Println(strings.Contains(message, "World")) // true

Split

Split a string into a slice of substrings.

fmt.Println(strings.Split(message, " ")) // ["Hello", "World!"]

Replace

Replace occurrences of a substring.

fmt.Println(strings.Replace(message, "World", "Go", 1)) // "Hello Go!"

1. String Iteration:

   • In Go, strings are UTF-8 encoded, which means characters can be multi-byte. If you need to iterate over the string’s characters, you should use the range loop, which properly handles multi-byte characters.

   message := "Hello World!"
   for index, char := range message {
       fmt.Printf("Character %c at index %d\n", char, index)
   }

2. Rune (Character) vs Byte:

   • Strings in Go are made up of bytes, but you may want to work with individual characters (runes) for proper handling of multi-byte characters like non-ASCII symbols. Use the rune type for characters.

   message := "Hello"
   fmt.Printf("First character as rune: %c\n", rune(message[0]))

3. String to Rune Conversion:

   • If you need to convert a string to a slice of runes (for better manipulation of characters), you can easily convert it.

   message := "GoLang"
   runes := []rune(message)
   fmt.Println("String as runes:", runes)

4. Check if a string is empty:

   • To check if a string is empty, you can directly compare it with an empty string.

   message := ""
   if message == "" {
       fmt.Println("The string is empty.")
   }

5. String Join:

   • Sometimes, you may need to join an array or slice of strings into a single string. The strings.Join function allows you to do that.

   words := []string{"Hello", "World", "Go"}
   fmt.Println(strings.Join(words, " ")) // "Hello World Go"

6. String Contains, Prefix, and Suffix:

   • For more advanced string searching, Go provides additional functions like strings.HasPrefix and strings.HasSuffix.

   message := "Hello World!"
   fmt.Println(strings.HasPrefix(message, "Hello")) // true
   fmt.Println(strings.HasSuffix(message, "World!")) // true

7. String Reversal:

   • Go doesn’t have a built-in function for reversing strings, but you can easily implement it using a loop.

   message := "GoLang"
   reversed := []rune(message)
   for i, j := 0, len(reversed)-1; i < j; i, j = i+1, j-1 {
       reversed[i], reversed[j] = reversed[j], reversed[i]
   }
   fmt.Println(string(reversed)) // "gnaoG"

Go String Operations & Methods