Data Types in Go
Data types specify the type of data that a valid Go variable can hold. In Go language, the type is divided into four categories which are as follows:
- Basic type: Numbers, strings, and booleans come under this category.
- Aggregate type: Array and structs come under this category.
- Reference type: Pointers, slices, maps, functions, and channels come under this category.
- Interface type
Here, we will discuss Basic Data Types in the Go language. The Basic Data Types are further categorized into three subcategories which are:
- Numbers
- Booleans
- Strings
Numbers
In Go language, numbers are divided into three sub-categories that are:
- Integers: In Go language, both signed and unsigned integers are available in four different sizes as shown in the below table. The signed int is represented by int and the unsigned integer is represented by uint.
Data Type | Description |
|---|---|
| int8 | 8-bit signed integer |
| int16 | 16-bit signed integer |
| int32 | 32-bit signed integer |
| int64 | 64-bit signed integer |
| uint8 | 8-bit unsigned integer |
| uint16 | 16-bit unsigned integer |
| uint32 | 32-bit unsigned integer |
| uint64 | 64-bit unsigned integer |
| int | Both in and uint contain same size, either 32 or 64 bit. |
| uint | Both in and uint contain same size, either 32 or 64 bit. |
| rune | It is a synonym of int32 and also represent Unicode code points. |
| byte | It is a synonym of int8. |
| uintptr | It is an unsigned integer type. Its width is not defined, but its can hold all the bits of a pointer value. |
Example:
Go
// Go program to illustrate// the use of integerspackage mainimport "fmt" func main() { // Using 8-bit unsigned int var X uint8 = 225 fmt.Println(X, X-3) // Using 16-bit signed int var Y int16 = 32767 fmt.Println(Y+2, Y-2)} |
Output:
225 222 -32767 32765
- Floating-Point Numbers: In Go language, floating-point numbers are divided into two categories as shown in the below table:
| Data Type | Description |
|---|---|
| float32 | 32-bit IEEE 754 floating-point number |
| float64 | 64-bit IEEE 754 floating-point number |
Example:
Go
// Go program to illustrate// the use of floating-point// numberspackage mainimport "fmt" func main() { a := 20.45 b := 34.89 // Subtraction of two // floating-point number c := b-a // Display the result fmt.Printf("Result is: %f", c) // Display the type of c variable fmt.Printf("\nThe type of c is : %T", c) } |
Output:
Result is: 14.440000 The type of c is : float64
- Complex Numbers: The complex numbers are divided into two parts are shown in the below table. float32 and float64 are also part of these complex numbers. The in-built function creates a complex number from its imaginary and real part and in-built imaginary and real function extract those parts.
| Data Type | Description |
|---|---|
| complex64 | Complex numbers which contain float32 as a real and imaginary component. |
| complex128 | Complex numbers which contain float64 as a real and imaginary component. |
Example:
Go
// Go program to illustrate// the use of complex numberspackage mainimport "fmt"func main() { var a complex128 = complex(6, 2) var b complex64 = complex(9, 2) fmt.Println(a) fmt.Println(b) // Display the type fmt.Printf("The type of a is %T and "+ "the type of b is %T", a, b)} |
Output:
(6+2i) (9+2i) The type of a is complex128 and the type of b is complex64
Booleans
The boolean data type represents only one bit of information either true or false. The values of type boolean are not converted implicitly or explicitly to any other type.
Example:
Go
// Go program to illustrate// the use of booleanspackage mainimport "fmt"func main() { // variables str1 := "GeeksforGeeks" str2:= "geeksForgeeks" str3:= "GeeksforGeeks" result1:= str1 == str2 result2:= str1 == str3 // Display the result fmt.Println( result1) fmt.Println( result2) // Display the type of // result1 and result2 fmt.Printf("The type of result1 is %T and "+ "the type of result2 is %T", result1, result2) } |
Output:
false true The type of result1 is bool and the type of result2 is bool
Strings
The string data type represents a sequence of Unicode code points. Or in other words, we can say a string is a sequence of immutable bytes, means once a string is created you cannot change that string. A string may contain arbitrary data, including bytes with zero value in the human-readable form.
Example:
Go
// Go program to illustrate// the use of stringspackage mainimport "fmt"func main() { // str variable which stores strings str := "GeeksforGeeks" // Display the length of the string fmt.Printf("Length of the string is:%d", len(str)) // Display the string fmt.Printf("\nString is: %s", str) // Display the type of str variable fmt.Printf("\nType of str is: %T", str)} |
Output:
Length of the string is:13 String is: GeeksforGeeks Type of str is: string
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