Lua關係運算符

下表列出了所有的Lua語言支持的關係運算符。假設變量A持有10和變量B持有20則：

運算符

描述

示例

==

檢查兩個操作數的值是否相等，如果是則條件變爲真。

(A == B) 不爲 true.

~=

檢查兩個操作數的值是否相等，如果值不相等，則條件變爲真。

(A ~= B) 爲 true.

>

檢查左操作數的值是否大於右操作數的值，如果是，則條件成立。

(A > B) 不爲 true.

<

檢查左操作數的值是否小於右操作數的值，如果是，則條件成立。

(A < B)  爲  true.

>=

檢查左操作數的值是否大於或等於右操作數的值，如果是，則條件成立。

(A >= B) 不爲 true.

<=

檢查左操作數的值是否小於或等於右操作數的值，如果是，則條件成立。

(A <= B)  爲  true.

示例

試試下面的例子就明白了所有的Lua編程語言提供的關係運算符：

a = 21 b = 10 if( a == b ) then print("Line 1 - a is equal to b" ) else print("Line 1 - a is not equal to b" ) end if( a ~= b ) then print("Line 2 - a is not equal to b" ) else print("Line 2 - a is equal to b" ) end if ( a < b ) then print("Line 3 - a is less than b" ) else print("Line 3 - a is not less than b" ) end if ( a > b ) then print("Line 4 - a is greater than b" ) else print("Line 5 - a is not greater than b" ) end -- Lets change value of a and b
a = 5 b = 20 if ( a <= b ) then print("Line 5 - a is either less than or equal to b" ) end if ( b >= a ) then print("Line 6 - b is either greater than or equal to b" ) end

當建立並執行上面的程序它會產生以下結果：

Line 1 - a is not equal to b
Line 2 - a is not equal to b
Line 3 - a is not less than b
Line 4 - a is greater than b
Line 5 - a is either less than or equal to b
Line 6 - b is either greater than or equal to b