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📜  JavaScript运算符

📅  最后修改于: 2020-10-23 14:20:26             🧑  作者: Mango

JavaScript运算子

JavaScript运算符符是用于对操作数执行操作的符号。例如：

var sum=10+20;

在这里，+是算术运算运算符，=是赋值运算符。

JavaScript中有以下类型的运算符。

  • 算术运算符
  • 比较(关系)运算符
  • 按位运算符
  • 逻辑运算符
  • 赋值运算符
  • 特殊操作员

JavaScript算术运算符

算术运算运算符用于对操作数执行算术运算。以下运算符称为JavaScript算术运算运算符。

Operator Description Example
+ Addition 10+20 = 30
– Subtraction 20-10 = 10
* Multiplication 10*20 = 200
/ Division 20/10 = 2
% Modulus (Remainder) 20%10 = 0
++ Increment var a=10; a++; Now a = 11
— Decrement var a=10; a–; Now a = 9

JavaScript比较运算符

JavaScript的比较运算符的两个操作数进行比较。运算符如下：

Operator Description Example
== Is equal to 10==20 = false
=== Identical (equal and of same type) 10==20 = false
!= Not equal to 10!=20 = true
!== Not Identical 20!==20 = false
> Greater than 20>10 = true
>= Greater than or equal to 20>=10 = true
< Less than 20<10 = false
<= Less than or equal to 20<=10 = false

JavaScript按位运算符

按位运算运算符对操作数执行按位运算。按位运算运算符如下：

Operator Description Example
& Bitwise AND (10==20 & 20==33) = false
| Bitwise OR (10==20 | 20==33) = false
^ Bitwise XOR (10==20 ^ 20==33) = false
~ Bitwise NOT (~10) = -10
<< Bitwise Left Shift (10<<2) = 40
>> Bitwise Right Shift (10>>2) = 2
>>> Bitwise Right Shift with Zero (10>>>2) = 2

JavaScript逻辑运算符

以下运算符称为JavaScript逻辑运算符。

Operator Description Example
&& Logical AND (10==20 && 20==33) = false
|| Logical OR (10==20 || 20==33) = false
! Logical Not !(10==20) = true

JavaScript赋值运算符

以下运算符称为JavaScript赋值运算符。

Operator Description Example
= Assign 10+10 = 20
+= Add and assign var a=10; a+=20; Now a = 30
-= Subtract and assign var a=20; a-=10; Now a = 10
*= Multiply and assign var a=10; a*=20; Now a = 200
/= Divide and assign var a=10; a/=2; Now a = 5
%= Modulus and assign var a=10; a%=2; Now a = 0

JavaScript特殊运算符

以下运算符被称为JavaScript特殊运算符。

Operator Description
(?:) Conditional Operator returns value based on the condition. It is like if-else.
, Comma Operator allows multiple expressions to be evaluated as single statement.
delete Delete Operator deletes a property from the object.
in In Operator checks if object has the given property
instanceof checks if the object is an instance of given type
new creates an instance (object)
typeof checks the type of object.
void it discards the expression’s return value.
yield checks what is returned in a generator by the generator’s iterator.