Lua - 关系运算符

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  简述

  下表显示了 Lua 语言支持的所有关系运算符。假设变量A 容纳 10 和变量 B 持有 20 然后 -

  操作符	描述	例子
  ==	检查两个操作数的值是否相等，如果是，则条件为真。	(A == B) 不为真。
  ~=	检查两个操作数的值是否相等，如果值不相等则条件为真。	(A ~= B) 为真。
  >	检查左操作数的值是否大于右操作数的值，如果是，则条件为真。	(A > B) 为假。
  <	检查左操作数的值是否小于右操作数的值，如果是，则条件为真。	(A < B) 为真。
  >=	检查左操作数的值是否大于或等于右操作数的值，如果是，则条件为真。	(A >= B) 不为真。
  <=	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) 为真。

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  例子

  尝试以下示例以了解 Lua 编程语言中可用的所有关系运算符 -

  
  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
  

  当您构建并执行上述程序时，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