Go language basic conditional statement if

if It's a conditional statement .if The syntax of the sentence is

if condition {  
/*  stay condition by  true  When the  */
}

This is a single conditional statement ,condition by true when , Execute the code in the condition

if condition {
   /*  stay condition by  true  When the  */
} else {
  /*  stay condition by  false  When the  */
}

If condition by true when , Execute above { Code } Code between , If false when , perform else Code inside

if condition 1 {
   /*  stay condition1 by  true  When the  */
} else if condition 2 {
  /*  stay condition2 by  true  When the  */
}else {
/*  stay condition1 and condition2 All for  false  When the  */
}

The order of condition judgment is from top to bottom . If if or else if The result of conditional judgment is true , Then execute the corresponding code block . If no condition is true , be else The code block is executed .

if condition 1 {
   /* condition 1  by  true  When the  */
   if condition 2 {
      /* condition 2  by  true  When the  */
   }
}

This statement only satisfies the condition 1, Then the condition will be carried out 2 The judgment of the , If the condition 1 Are not satisfied , Will not judge the conditions 2

• else The statement should be in if Braces for statements } In the same line after that . If not , The compiler will not pass .

package main

import "fmt"

func test1() {
	// if Conditions only make judgments 
	num := 10
	if num >= 0 && num < 10 {
		fmt.Println("0 <= num<10")
	} else if num >= 10 && num < 20 {
		fmt.Println("10<= num <20")
	} else {
		fmt.Println("num  be not in 0~20 Between ")
	}
}

func test2() {
	// if The condition is assigned first , And then make a judgment 
	if num := 10; num >= 0 && num < 10 {
		fmt.Println("0 <= num<10")
	} else if num >= 10 && num < 20 {
		fmt.Println("10<= num <20")
	} else {
		fmt.Println("num  be not in 0~20 Between ")
	}
}

func main() {
	test1()
	test2()
}

these two items. test The running result of is the same , But these two test Inside num The scope of is different ,test1 Inside num The scope of is the whole test1,test2 Inside num Only in if The conditions take effect