Understanding Data Types in Go

Go has three basic data types:

1. Bool
2. Numerical
3. String

1. This program shows some of the different data types in Go

   package main
   import "fmt"
   
   func main() {
   	var a bool = true          // Boolean
   	var b int = 5              // Integer
   	var c float32 = 6.14       // Floating point number
   	var d string = "PRWATECH!" // String
   
   	fmt.Println("Boolean: ", a)
   	fmt.Println("Integer: ", b)
   	fmt.Println("Float:   ", c)
   	fmt.Println("String:  ", d)
   }	
   

   Output :

   PS C:\GO_Language\datatype> go run type.go
   Boolean:  true
   Integer:  5
   Float:    6.14
   String:   PRWATECH!
   

2. Boolean data type: datatype is declared with the bool keyword and can take the values true or false.
   1. This program shows some different ways to declare Boolean variables:

      package main
      import "fmt"
      func main() {
          var b1 bool = true
          var b2 = true
          var b3 bool
          b4 := true
          fmt.Println(b1)
          fmt.Println(b2)
          fmt.Println(b3)
          fmt.Println(b4)
      }
      

      Output :

      PS C:\GO_Language\datatype> go run bool.go
      true
      true
      false
      true
      

• • • Integer data type: are used to store a whole no. without decimals, like 35.50.

• • • Integer has two types:
      1. Signed integers
      2. Unsigned integers

       

      • Singed integer:

      Signed integers, declared with one of the int keywords, can store both positive and negative values

      package main
      
      import "fmt"
      
      func main() {
          var x int = 50
          var y int = 40
          fmt.Printf("Type: %T, value: %v \n", x, x)
          fmt.Printf("Type: %T, value: %v", y, y)
      }
      

      Output :

      PS C:\GO_Language\datatype> go run int1.go
      Type: int, value: 50 
      Type: int, value: 40
      

•          Unsigned integers:

Unsigned integers, declared with one of the uint keywords, can only store non-negative values:

package main
import "fmt"

func main() {
    var x uint = 50
    var y uint = 450

    fmt.Printf("Type: %T, value: %v \n", x, x)
    fmt.Printf("Type: %T, value: %v", y, y)
}

Output :

PS C:\GO_Language\datatype> go run int2.go
  
Type: uint, value: 50 
Type: uint, value: 450

3)float data type:

 are used to store positive and negative no. which a decimal point, like 35.3, -32, to 3423.243525.

Type                           size                              Range

Float32                        32bits                          -34e+38 to 3.4e+38.

Float64                        64bits                          -1.7e+308 to 3.4e+308.

This program shows how to declare some variables of type float32:

package main

import "fmt"

func main() {
    var x float32 = 23.78
    var y float32 = 3.4e+38

    fmt.Printf("Type: %T, value: %v\n", x, x)
    fmt.Printf("Type: %T, value: %v", y, y)
}

output :

PS C:\GO_Language\datatype> go run float1.go
  
Type: float32, value: 23.78
Type: float32, value: 3.4e+38

This Progeam shows how to declare a variable of type float64:

package main
import "fmt"

func main() {
    var x float64 = 1.7e+308
    
    fmt.Printf("Type: %T, value: %v", x, x)
    
}

check output :

PS C:\GO_Language\datatype> go run float2.go
   
Type: float64, value: 1.7e+308

3)String Data type: the string datatype is use to store a sequence of characters. String values must be surround by double quotes:

package main

import "fmt"

func main() {
    var txt1 string = "parwatech"
    var txt2 string
    txt3 := "World 1"

    fmt.Printf("Type: %T, value: %\n", txt1, txt1)
    fmt.Printf("Type: %T, value: %v\n", txt2, txt2)
    fmt.Printf("Type: %T, value: %v\n", txt3, txt3)
}

output:

PS C:\GO_Language\datatype> go run str.go   
 
Type: string, value: parwatech 
Type: string, value:  
Type: string, value: World 1

Understanding Data Types in Go