发布于 2015-07-26 14:47:54 | 181 次阅读 | 评论: 0 | 来源: 网络整理
下表列出了所有的Lua语言支持的关系运算符。假设变量A持有10和变量B持有20则：
| 运算符 | 描述 | 示例 |
|---|---|---|
| == | 检查两个操作数的值是否相等，如果是则条件变为真。 | (A == B) 不为 true. |
| ~= | 检查两个操作数的值是否相等，如果值不相等，则条件变为真。 | (A ~= B) 为 true. |
| > | 检查左操作数的值是否大于右操作数的值，如果是，则条件成立。 | (A > B) 不为 true. |
| < | 检查左操作数的值是否小于右操作数的值，如果是，则条件成立。 | (A < B) 为 true. |
| >= | 检查左操作数的值是否大于或等于右操作数的值，如果是，则条件成立。 | (A >= B) 不为 true. |
| <= | 检查左操作数的值是否小于或等于右操作数的值，如果是，则条件成立。 | (A <= B) 为 true. |
试试下面的例子就明白了所有的Lua编程语言提供的关系运算符：
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
当建立并执行上面的程序它会产生以下结果：
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