Integer data types are used to store a whole number without decimals, like 35, -50, or 1345000.
The integer data type has two categories:
- Signed integers - can store both positive and negative values
- Unsigned integers - can only store non-negative values
Tip
The default type for integer is int . If you do not specify a type, the type will be int .
Signed Integers
Signed integers, declared with one of the int keywords, can store both positive and negative values:
Example
package main
import ("fmt")
func main() {
var x int = 500
var y int = -4500
fmt.Printf("Type: %T, value: %v", x, x)
fmt.Printf("Type: %T, value: %v", y, y)
}Go has five keywords/types of signed integers:
| Type | Size | Range |
|---|---|---|
| int | Depends on platform: 32 bits in 32 bit systems and 64 bit in 64 bit systems | -2147483648 to 2147483647 in 32 bit systems and -9223372036854775808 to 9223372036854775807 in 64 bit systems |
| int8 | 8 bits/1 byte | -128 to 127 |
| int16 | 16 bits/2 byte | -32768 to 32767 |
| int32 | 32 bits/4 byte | -2147483648 to 2147483647 |
| int64 | 64 bits/8 byte | -9223372036854775808 to 9223372036854775807 |
Unsigned Integers
Unsigned integers, declared with one of the uint keywords, can only store non-negative values:
Example
package main
import ("fmt")
func main() {
var x uint = 500
var y uint = 4500
fmt.Printf("Type: %T, value: %v", x, x)
fmt.Printf("Type: %T, value: %v", y, y)
}Go has five keywords/types of unsigned integers:
| Type | Size | Range |
|---|---|---|
| uint | Depends on platform: 32 bits in 32 bit systems and 64 bit in 64 bit systems | 0 to 4294967295 in 32 bit systems and 0 to 18446744073709551615 in 64 bit systems |
| uint8 | 8 bits/1 byte | 0 to 255 |
| uint16 | 16 bits/2 byte | 0 to 65535 |
| uint32 | 32 bits/4 byte | 0 to 4294967295 |
| uint64 | 64 bits/8 byte | 0 to 18446744073709551615 |
Which Integer Type to Use?
The type of integer to choose, depends on the value the variable has to store.
Example
package main
import ("fmt")
func main() {
var x int8 = 1000
fmt.Printf("Type: %T, value: %v", x, x)
}