Operator =（等于）

• 来源: https://www.freebasic.net/wiki/wikka.php?wakka=KeyPgOpEqual
• 最后更新: 2016-03-13

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比较两个表达式是否相等

语法

declare operator = ( byref lhs as byte, byref rhs as byte ) as integer
declare operator = ( byref lhs as ubyte, byref rhs as ubyte ) as integer
declare operator = ( byref lhs as short, byref rhs as short ) as integer
declare operator = ( byref lhs as ushort, byref rhs as ushort ) as integer
declare operator = ( byref lhs as integer, byref rhs as integer ) as integer
declare operator = ( byref lhs as uinteger, byref rhs as uinteger ) as integer
declare operator = ( byref lhs as longint, byref rhs as longint ) as integer
declare operator = ( byref lhs as ulongint, byref rhs as ulongint ) as integer

declare operator = ( byref lhs as single, byref rhs as single ) as integer
declare operator = ( byref lhs as double, byref rhs as double ) as integer

declare operator = ( byref lhs as string, byref rhs as string ) as integer
declare operator = ( byref lhs as zstring, byref rhs as zstring ) as integer
declare operator = ( byref lhs as wstring, byref rhs as wstring ) as integer

declare operator = ( byref lhs as T, byref rhs as T ) as integer

declare operator = ( byref lhs as boolean, byref rhs as boolean ) as boolean

用法

result = lhs = rhs

参数

lhs

要比较的左侧表达式。

rhs

要比较的右侧表达式。

T

任何指针类型。

返回值

如果表达式相等，返回负一 (-1)；如果不相等，返回零 (0)。

描述

Operator =（等于）是一个二元运算符，比较两个表达式是否相等并返回结果——主要以 Integer 形式表示的布尔值：真为负一 (-1)，假为零 (0)。仅当左右两侧类型都是 Boolean 时，返回类型才也是 Boolean。参数不会以任何方式被修改。

此运算符也可以重载以接受用户定义类型。

Operator =（等于）不应与初始化或赋值混淆，两者也使用 "=" 符号。

示例

start GeSHi

Dim i As Integer = 0    '' 初始化：将 i 初始化为 0
i = 420                 '' 赋值：将值 420 赋给 i

If (i = 69) Then        '' 等式：比较 i 的值和 69 是否相等
    Print "serious error: i should equal 420"
    End -1
End If

end GeSHi

Operator <>（不等于）是 Operator =（等于）的互补，与 Operator Not（按位取反）组合时功能相同。

start GeSHi

   If (420 = 420) Then Print "(420 = 420) is true."
   If Not (69 <> 69) Then Print "not (69 <> 69) is true."

end GeSHi

方言差异

• 在 -lang qb 方言中，此运算符不能被重载。

与 QB 的区别

• 无

参见

• Operator <>（不等于）
• Operator =[>]（赋值）

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