运算符优先级_程序开发

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2023-01-29 01:00:03

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C++运算符优先级
Precedence	Operator	Description	Associativity
1	`::`	Scope resolution	Left-to-right
2	`++` `--`	Suffix/postfix increment and decrement
	`()`	Function call
	`[]`	Array subscripting
	`.`	Element selection by reference
	`−>`	Element selection through pointer
3	`++` `--`	Prefix increment and decrement	Right-to-left
	`+` `−`	Unary plus and minus
	`!` `~`	Logical NOT and bitwise NOT
	`(type)`	Type cast
	`*`	Indirection (dereference)
	`&`	Address-of
	`sizeof`	Size-of
	`new`, `new[]`	Dynamic memory allocation
	`delete`, `delete[]`	Dynamic memory deallocation
4	`.` `->`	Pointer to member	Left-to-right
5	`*` `/` `%`	Multiplication, division, and remainder
6	`+` `−`	Addition and subtraction
7	`<<` `>>`	Bitwise left shift and right shift
8	`<` `<=`	For relational operators < and ≤ respectively
8	`>` `>=`	For relational operators > and ≥ respectively
9	`==` `!=`	For relational = and ≠ respectively
10	`&`	Bitwise AND
11	`^`	Bitwise XOR (exclusive or)
12	`\|`	Bitwise OR (inclusive or)
13	`&&`	Logical AND
14	`\|\|`	Logical OR
15	`?:`	Ternary conditional	Right-to-Left
16	`=`	Direct assignment (provided by default for C++ classes)
	`+=` `−=`	Assignment by sum and difference
	`*=` `/=` `%=`	Assignment by product, quotient, and remainder
	`<<=` `>>=`	Assignment by bitwise left shift and right shift
	`&=` `^=` `\|=`	Assignment by bitwise AND, XOR, and OR
17	`throw`	Throw operator (for exceptions)
18	`,`	Comma	Left-to-right

C语言运算符优先级
Precedence	Operator	Description	Associativity
1	`++` `--`	Suffix/postfix increment and decrement	Left-to-right
	`()`	Function call
	`[]`	Array subscripting
	`.`	Structure and union member access
	`−>`	Structure and union member access through pointer
	`(type){list}`	Compound literal(C99)
2	`++` `--`	Prefix increment and decrement	Right-to-left
	`+` `−`	Unary plus and minus
	`!` `~`	Logical NOT and bitwise NOT
	`(type)`	Type cast
	`*`	Indirection (dereference)
	`&`	Address-of
	`sizeof`	Size-of
	`_Alignof`	Alignment requirement(C11)
3	`*` `/` `%`	Multiplication, division, and remainder	Left-to-right
4	`+` `−`	Addition and subtraction
5	`<<` `>>`	Bitwise left shift and right shift
6	`<` `<=`	For relational operators < and ≤ respectively
6	`>` `>=`	For relational operators > and ≥ respectively
7	`==` `!=`	For relational = and ≠ respectively
8	`&`	Bitwise AND
9	`^`	Bitwise XOR (exclusive or)
10	`\|`	Bitwise OR (inclusive or)
11	`&&`	Logical AND
12	`\|\|`	Logical OR
13	`?:`	Ternary conditional	Right-to-Left
14	`=`	Simple assignment
	`+=` `−=`	Assignment by sum and difference
	`*=` `/=` `%=`	Assignment by product, quotient, and remainder
	`<<=` `>>=`	Assignment by bitwise left shift and right shift
	`&=` `^=` `\|=`	Assignment by bitwise AND, XOR, and OR
15	`,`	Comma	Left-to-right

PHP运算符优先级
结合方向	运算符	附加信息
非结合	`clone new`	clone 和 new
左	`[`	array()
非结合	`++ --`	递增／递减运算符
非结合	`~ - (int) (float) (string) (array) (object) (bool) @`	类型
非结合	`instanceof`	类型
右结合	`!`	逻辑操作符
左	`* / %`	算术运算符
左	`+ - .`	算术运算符和字符串运算符
左	`<< >>`	位运算符
非结合	`< <= > >= <>`	比较运算符
非结合	`== != === !==`	比较运算符
左	`&`	位运算符和引用
左	`^`	位运算符
左	`\|`	位运算符
左	`&&`	逻辑运算符
左	`\|\|`	逻辑运算符
左	`? :`	三元运算符
右	`= += -= *= /= .= %= &= \|= ^= <<= >>=`	赋值运算符
左	`and`	逻辑运算符
左	`xor`	逻辑运算符
左	`or`	逻辑运算符
左	`,`	多处用到

这个表给出Python的运算符优先级（从低到高）.

从最低的优先级（最松散地结合）到最高的优先级（最紧密地结合）。

这意味着在一个表达式中，Python会首先计算表中较下面的运算符，然后在计算列在表上部的运算符。