May 18, 2021 WeChat Mini Program Development Document
Example code:
var a = 10, b = 20;
// 加法运算
console.log(30 === a + b);
// 减法运算
console.log(-10 === a - b);
// 乘法运算
console.log(200 === a * b);
// 除法运算
console.log(0.5 === a / b);
// 取余运算
console.log(10 === a % b);
var a = '.w' , b = 'xs';
// 字符串拼接
console.log('.wxs' === a + b);
Example code:
var a = 10, b = 20;
// 自增运算
console.log(10 === a++);
console.log(12 === ++a);
// 自减运算
console.log(12 === a--);
console.log(10 === --a);
// 正值运算
console.log(10 === +a);
// 负值运算
console.log(0-10 === -a);
// 否运算
console.log(-11 === ~a);
// 取反运算
console.log(false === !a);
// delete 运算
console.log(true === delete a.fake);
// void 运算
console.log(undefined === void a);
// typeof 运算
console.log("number" === typeof a);
Example code:
var a = 10, b = 20;
// 左移运算
console.log(80 === (a << 3));
// 无符号右移运算
console.log(2 === (a >> 2));
// 带符号右移运算
console.log(2 === (a >>> 2));
// 与运算
console.log(2 === (a & 3));
// 异或运算
console.log(9 === (a ^ 3));
// 或运算
console.log(11 === (a | 3));
Example code:
var a = 10, b = 20;
// 小于
console.log(true === (a < b));
// 大于
console.log(false === (a > b));
// 小于等于
console.log(true === (a <= b));
// 大于等于
console.log(false === (a >= b));
Example code:
var a = 10, b = 20;
// 等号
console.log(false === (a == b));
// 非等号
console.log(true === (a != b));
// 全等号
console.log(false === (a === b));
// 非全等号
console.log(true === (a !== b));
Example code:
var a = 10;
a = 10; a *= 10;
console.log(100 === a);
a = 10; a /= 5;
console.log(2 === a);
a = 10; a %= 7;
console.log(3 === a);
a = 10; a += 5;
console.log(15 === a);
a = 10; a -= 11;
console.log(-1 === a);
a = 10; a <<= 10;
console.log(10240 === a);
a = 10; a >>= 2;
console.log(2 === a);
a = 10; a >>>= 2;
console.log(2 === a);
a = 10; a &= 3;
console.log(2 === a);
a = 10; a ^= 3;
console.log(9 === a);
a = 10; a |= 3;
console.log(11 === a);
Example code:
var a = 10, b = 20;
// 逻辑与
console.log(20 === (a && b));
// 逻辑或
console.log(10 === (a || b));
Example code:
var a = 10, b = 20;
//条件运算符
console.log(20 === (a >= 10 ? a + 10 : b + 10));
//逗号运算符
console.log(20 === (a, b));
Priority | Operator | Description | Binding |
---|---|---|---|
20 |
(
...
)
|
Brackets | n/a |
19 |
...
.
...
|
Member access | Left to right |
...
[
...
]
|
Member access | Left to right | |
...
(
...
)
|
The function is called | Left to right | |
17 |
...
++
|
Post-increment | n/a |
...
--
|
The post is decreasing | n/a | |
16 |
!
...
|
Logic is not | Right to left |
~
...
|
By bit non | Right to left | |
+
...
|
One dollar plus method | Right to left | |
-
...
|
One-dollar subtract | Right to left | |
++
...
|
Pre-increment | Right to left | |
--
...
|
The front is decreasing | Right to left | |
typeof
...
|
typeof | Right to left | |
void
...
|
void | Right to left | |
delete
...
|
delete | Right to left | |
14 |
...
*
...
|
Multiplication | Left to right |
...
/
...
|
Division | Left to right | |
...
%
...
|
Molding | Left to right | |
13 |
...
+
...
|
Addition | Left to right |
...
-
...
|
Subtraction | Left to right | |
12 |
...
<<
...
|
Move left by bit | Left to right |
...
>>
...
|
Move right by bit | Left to right | |
...
>>>
...
|
Unsigned right shift | Left to right | |
11 |
...
<
...
|
Less than | Left to right |
...
<=
...
|
Less than or equal to | Left to right | |
...
>
...
|
Greater than | Left to right | |
...
>=
...
|
Is greater than or equal to | Left to right | |
10 |
...
==
...
|
Equals | Left to right |
...
!=
...
|
Non-equal sign | Left to right | |
...
===
...
|
Full equivalent | Left to right | |
...
!==
...
|
Non-full equal sign | Left to right | |
9 |
...
&
...
|
By bit with | Left to right |
8 |
...
^
...
|
By bit or | Left to right |
7 |
...
|
...
|
By bit or | Left to right |
6 |
...
&&
...
|
Logic and | Left to right |
5 |
...
||
...
|
Logic or | Left to right |
4 |
...
?
...
:
...
|
Conditional operator | Right to left |
3 |
...
=
...
|
Assignment | Right to left |
...
+=
...
|
Assignment | Right to left | |
...
-=
...
|
Assignment | Right to left | |
...
*=
...
|
Assignment | Right to left | |
...
/=
...
|
Assignment | Right to left | |
...
%=
...
|
Assignment | Right to left | |
...
<<=
...
|
Assignment | Right to left | |
...
>>=
...
|
Assignment | Right to left | |
...
>>>=
...
|
Assignment | Right to left | |
...
&=
...
|
Assignment | Right to left | |
...
^=
...
|
Assignment | Right to left | |
...
|=
...
|
Assignment | Right to left | |
0 |
...
,
...
|
Comma | Left to right |