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📜  Elixir-运算符

📅  最后修改于: 2020-11-04 08:22:08             🧑  作者: Mango

 

运算符是一个符号，告诉编译器执行特定的数学或逻辑操作。 elixir提供了很多运算符。它们分为以下类别-

  • 算术运算运算符
  • 运算符
  • 布尔运算符
  • 杂项运算符

算术运算符

下表显示了Elixir语言支持的所有算术运算运算符。假设变量A持有10，变量B持有20，则-

显示范例

Operator Description Example
+ Adds 2 numbers. A + B will give 30
– Subtracts second number from first. A-B will give -10
* Multiplies two numbers. A*B will give 200
/ Divides first number from second. This casts the numbers in floats and gives a float result A/B will give 0.5.
div This function is used to get the quotient on division. div(10,20) will give 0
rem This function is used to get the remainder on division. rem(A, B) will give 10

比较运算符

在药剂比较运算符大多是通用于大多数其他语言所提供的。下表中药剂总结了运算符。假设变量A持有10，变量B持有20，则-

显示范例

Operator Description Example
== Checks if value on left is equal to value on right(Type casts values if they are not the same type). A == B will give false
!= Checks if value on left is not equal to value on right. A != B will give true
=== Checks if type of value on left equals type of value on right, if yes then check the same for value. A === B will give false
!== Same as above but checks for inequality instead of equality. A !== B will give true
> Checks if the value of left operand is greater than the value of right operand; if yes, then the condition becomes true. A > B will give false
< Checks if the value of left operand is less than the value of right operand; if yes, then the condition becomes true. A < B will give true
>= Checks if the value of left operand is greater than or equal to the value of right operand; if yes, then the condition becomes true. A >= B will give false
<= Checks if the value of left operand is less than or equal to the value of right operand; if yes, then the condition becomes true. A <= B will give true

逻辑运算符

Elixir提供6个逻辑运算符：和，或不，&&，||和！前三个，并且还是不严格的布尔运算符，这意味着他们希望自己的第一个参数是一个布尔值。非布尔参数将引发错误。而下三个&&，||和！是非严格的，不要求我们严格地将布尔值作为第一个值。他们的工作方式与严格的同行相同。假设变量A成立，变量B持有20，则-

显示范例

Operator Description Example
and Checks if both values provided are truthy, if yes then returns the value of second variable. (Logical and). A and B will give 20
or Checks if either value provided is truthy. Returns whichever value is truthy. Else returns false. (Logical or). A or B will give true
not Unary operator which inverts the value of given input. not A will give false
&& Non-strict and. Works same as and but does not expect first argument to be a Boolean. B && A will give 20
|| Non-strict or. Works same as or but does not expect first argument to be a Boolean. B || A will give true
! Non-strict not. Works same as not but does not expect the argument to be a Boolean. !A will give false

注意−和，或， &&和|| ||是短路运算符。这意味着，如果第一个参数是假的，那么就不会在第二个进一步的检查。并且，如果or的第一个参数为true，则不会检查第二个参数。例如，

false and raise("An error")  
#This won't raise an error as raise function wont get executed because of short
#circuiting nature of and operator

按位运算符

按位运算符对位进行运算并逐位执行操作。 Elixir提供Bitwise模块作为Bitwise包的一部分，因此，要使用这些模块，您需要使用bitwise模块。要使用它，请在您的shell中输入以下命令-

use Bitwise

对于以下示例，假设A为5，B为6-

显示范例

Operator Description Example
&&& Bitwise and operator copies a bit to result if it exists in both operands. A &&& B will give 4
||| Bitwise or operator copies a bit to result if it exists in either operand. A ||| B will give 7
>>> Bitwise right shift operator shifts first operand bits to the right by the number specified in second operand. A >>> B will give 0
<<< Bitwise left shift operator shifts first operand bits to the left by the number specified in second operand. A <<< B will give 320
^^^ Bitwise XOR operator copies a bit to result only if it is different on both operands. A ^^^ B will give 3
~~~ Unary bitwise not inverts the bits on the given number. ~~~A will give -6

杂项运算符

除上述运算符，Elixir还提供一系列其他运算符，例如串联运算符，匹配运算符，引脚运算符，管道运算符，字符串匹配运算符，代码点运算符，捕获运算符，三元运算符，这使其成为一门强大的语言。

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