下表列出了所有的Lua語(yǔ)言支持的關(guān)系運(yùn)算符。假設(shè)變量A持有10和變量B持有20則:
| 運(yùn)算符 | 描述 | 示例 |
|---|---|---|
| == | 檢查兩個(gè)操作數(shù)的值是否相等,如果是則條件變?yōu)檎妗?/td> | (A == B) 不為 true. |
| ~= | 檢查兩個(gè)操作數(shù)的值是否相等,如果值不相等,則條件變?yōu)檎妗?/td> | (A ~= B) 為 true. |
| > | 檢查左操作數(shù)的值是否大于右操作數(shù)的值,如果是,則條件成立。 | (A > B) 不為 true. |
| < | 檢查左操作數(shù)的值是否小于右操作數(shù)的值,如果是,則條件成立。 | (A < B) 為 true. |
| >= | 檢查左操作數(shù)的值是否大于或等于右操作數(shù)的值,如果是,則條件成立。 | (A >= B) 不為 true. |
| <= | 檢查左操作數(shù)的值是否小于或等于右操作數(shù)的值,如果是,則條件成立。 | (A <= B) 為 true. |
試試下面的例子就明白了所有的Lua編程語(yǔ)言提供的關(guān)系運(yùn)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(dāng)建立并執(zhí)行上面的程序它會(huì)產(chǎn)生以下結(jié)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