Golang Basics - string and int, Int64 inter conversion

Please look at the code.

package main

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

func main() {
    

	var testStr string = "123456"

	//  character string   turn  int
	intNum, _ := strconv.Atoi(testStr)
	fmt.Println("intNum =", intNum, ", intNum  The type is ", reflect.TypeOf(intNum))

	//  character string   turn  int64
	int64Num, _ := strconv.ParseInt(testStr, 10, 64)
	fmt.Println("int64Num=", int64Num, ", int64Num  The type is ", reflect.TypeOf(int64Num))

	// ===================================================

	// int  turn   character string 
	var intNum2 int = 123456
	var str1 string = strconv.Itoa(intNum2)
	fmt.Println("str1 =", str1, ", str1  The type is ", reflect.TypeOf(str1))

	// int64  turn   character string 
	var int64Num2 int64 = 123456
	var str2 string = strconv.FormatInt(int64Num2, 10)
	fmt.Println("str2 =", str2, ", str2  The type is ", reflect.TypeOf(str2))
}

Running results ：

intNum = 123456 , intNum  The type is  int
int64Num= 123456 , int64Num  The type is  int64
str1 = 123456 , str1  The type is  string      
str2 = 123456 , str2  The type is  string