golang --Converting and Checking Types

Posted 2022-08-15 saryli

package main

import (
	"fmt"
	"strconv"
)

func main() 
	strVar := "100"
	intVar, _ := strconv.Atoi(strVar)

	strVar1 := "-52541"
	intVar1, _ := strconv.ParseInt(strVar1, 10, 32)

	strVar2 := "101010101010101010"
	intVar2, _ := strconv.ParseInt(strVar2, 10, 64)

	fmt.Println(intVar, intVar1, intVar2)

　Package strconv implements conversions to and from string representations of basic data types. Atoi is equivalent to ParseInt(s, 10, 0), converted to type int. ParseInt interprets a string s in the given base (0, 2 to 36) and bit size (0 to 64) and returns the corresponding value i.

How to Convert string to float type in Go?

ParseFloat converts the string s to a floating-point number with the precision specified by bitSize: 32 for float32, or 64 for float64. When bitSize=32, the result still has type float64, but it will be convertible to float32 without changing its value.

package main

import (
	"fmt"
	"strconv"
)

func main() 
	s := "3.1415926535"
	f, _ := strconv.ParseFloat(s, 8)
	fmt.Printf("%T, %v\n", f, f)

	s1 := "-3.141"
	f1, _ := strconv.ParseFloat(s1, 8)
	fmt.Printf("%T, %v\n", f1, f1)

	s2 := "-3.141"
	f2, _ := strconv.ParseFloat(s2, 32)
	fmt.Printf("%T, %v\n", f2, f2)

　　

float64, 3.1415926535
float64, -3.141
float64, -3.1410000324249268

　

String to Boolean Data Type Conversion in Go

ParseBool returns the boolean value represented by the string. It accepts 1, t, T, TRUE, true, True, 0, f, F, FALSE, false, False. Any other value returns an error.

package main

import (
	"fmt"
	"strconv"
)

func main() 
	s1 := "true"
	b1, _ := strconv.ParseBool(s1)
	fmt.Printf("%T, %v\n", b1, b1)

	s2 := "t"
	b2, _ := strconv.ParseBool(s2)
	fmt.Printf("%T, %v\n", b2, b2)

	s3 := "0"
	b3, _ := strconv.ParseBool(s3)
	fmt.Printf("%T, %v\n", b3, b3)

	s4 := "F"
	b4, _ := strconv.ParseBool(s4)
	fmt.Printf("%T, %v\n", b4, b4)

　　

bool, true
bool, true
bool, false
bool, false

Convert Boolean Type to String in Go

FormatBool function used to convert Boolean variable into String.

 

package main

import (
	"fmt"
	"reflect"
	"strconv"
)

func main() 
	var b bool = true
	fmt.Println(reflect.TypeOf(b))

	var s string = strconv.FormatBool(b)
	fmt.Printf("%T, %v\n", s, s)
	fmt.Println(reflect.TypeOf(s))

　　

bool

string, true

string

 

How to Convert Float to String type in Go?

FormatFloat converts the floating-point number f to a string s.

package main

import (
	"fmt"
	"reflect"
	"strconv"
)

func main() 
	var f float64 = 3.1415926535
	fmt.Println(reflect.TypeOf(f))
	fmt.Println(f)

	var s string = strconv.FormatFloat(f, ‘E‘, -1, 32)

	fmt.Println(reflect.TypeOf(s))
	fmt.Println(s)

　　

float64
3.1415926535
string
3.1415927E+00

Convert Integer Type to String in Go

FormatInt converts the Integer number i to a String s.

package main

import (
	"fmt"
	"reflect"
	"strconv"
)

func main() 
	var i int64 = -654
	fmt.Println(reflect.TypeOf(i))
	fmt.Println(i)

	var s string = strconv.FormatInt(i, 10)
	fmt.Println(reflect.TypeOf(s))
	fmt.Println(s)

　　

int64
-654
string
-654

---

Convert Int to Int16 Int32 Int64 in Golang

package main

import (
	"fmt"
	"reflect"
)

func main() 
	var i int = 10
	fmt.Println(reflect.TypeOf(i))

	i16 := int16(i)
	fmt.Println(reflect.TypeOf(i16))

	i32 := int32(i)
	fmt.Println(reflect.TypeOf(i32))

	i64 := int64(i)
	fmt.Println(reflect.TypeOf(i64))

　　

int
int16
int32
int64

---

Convert Float32 to Float64 and Float64 to Float32 in Golang

package main

import (
	"fmt"
	"reflect"
)

func main() 
	var f32 float32 = 10.6556
	fmt.Println(reflect.TypeOf(f32))

	f64 := float64(f32)
	fmt.Println(reflect.TypeOf(f64))

	f64 = 1097.655698798798
	fmt.Println(f64)

	f32 = float32(f64)
	fmt.Println(f32)

　　

float32
float64
1097.655698798798
1097.6556

---

Convert Int to Float in Golang

package main

import (
	"fmt"
	"reflect"
)

func main() 
	var f32 float32 = 10.6556
	fmt.Println(reflect.TypeOf(f32))

	i32 := int32(f32)
	fmt.Println(reflect.TypeOf(i32))
	fmt.Println(i32)

	f64 := float64(i32)
	fmt.Println(reflect.TypeOf(f64))

　　

float32
int32
10
float64

---