Go語言關係運算子範例

2019-10-16 23:16:37

下表顯示了Go語言支援的所有關係運算子。假設變數 A 的值為 10,變數 B 的值為 20,則:

運算子 描述 範例
== 檢查兩個運算元的值是否相等,如果相等,則條件為真。 (A == B)結果為假
!= 檢查兩個運算元的值是否相等,如果值不相等,則條件為真。 (A != B)結果為真
> 檢查左運算元的值是否大於右運算元的值,如果是,則條件為真。 (A > B)結果為假
< 檢查左運算元的值是否小於右運算元的值,如果是,則條件為真。 (A < B)結果為真
>= 檢查左運算元的值是否大於或等於右運算元的值,如果是,則條件為真。 (A >= B)結果為假
<= 檢查左運算元的值是否小於或等於右運算元的值,如果是,則條件為真。 (A <= B)結果為真

範例

嘗試以下範例來了解Go程式設計語言中提供的所有關係運算子:

package main

import "fmt"

func main() {
   var a int = 21
   var b int = 10

   if( a == b ) {
      fmt.Printf("Line 1 - a is equal to b\n" )
   } else {
      fmt.Printf("Line 1 - a is not equal to b\n" )
   }
   if ( a < b ) {
      fmt.Printf("Line 2 - a is less than b\n" )
   } else {
      fmt.Printf("Line 2 - a is not less than b\n" )
   } 

   if ( a > b ) {
      fmt.Printf("Line 3 - a is greater than b\n" )
   } else {
      fmt.Printf("Line 3 - a is not greater than b\n" )
   }
   /* Lets change value of a and b */
   a = 5
   b = 20
   if ( a <= b ) {
      fmt.Printf("Line 4 - a is either less than or equal to  b\n" )
   }
   if ( b >= a ) {
      fmt.Printf("Line 5 - b is either greater than  or equal to b\n" )
   }
}

當編譯和執行上面程式,它產生以下結果:

Line 1 - a is not equal to b
Line 2 - a is not less than b
Line 3 - a is greater than b
Line 4 - a is either less than or equal to  b
Line 5 - b is either greater than  or equal to b