🚧table of operators

🚧 under construction -> fix table precedence

JS ⟩ statement ⟩ expression ⟩ operator ⟩ table of operators

⭐️ 重點

property access and invocation expressions have higher precedence than any of the operators.

👥 相關

• short-circuiting

📗 參考

• JavaScript: The Definitive Guide ⟩ 4.7 Operator Overview

📘 手冊

• Operator precedence ⟩

  • operator precedence table ⭐️

  • short-circuiting

• Expressions and operators

❓

問：「 Why a && b is (any, any) -> any 」❓

答：「 because it returns a if a is falsy, otherwise returns b. 」

• P：precedence, A：association, N：number of operands (arity)

• lval：lvalue, n：num, s：str, i：int, o：obj, f：func, b：bool, a：any

P	Operator	Operation	A	N	Types
18	( ... )	Grouping	🈚	null
17	obj . prop	property access	L	null
null	obj [ prop ]	computed property access	🈚	null
null	new F(args)	with argument list	🈚	null
null	f ( args )	Function Call	🈚	null
null	obj ?. prop	optional chaining	L	null
16	new F()	without argument list	🈚	null
15	++	post-increment	🈚	null
null	--	post-decrement	🈚	null
14	!	logical not	🈚	1	bool -> bool
0	~	bitwise not (invert bits)	🈚	1	int -> int
0	+	unary + (convert to number)	🈚	1	any -> num
0	-	unary - (negative)	🈚	1	num -> num
0	++	pre-increment	🈚	1	lval -> num
0	--	pre-decrement	🈚	1	lval -> num
0	typeof	type of operand	🈚	1	any -> str
0	delete	delete a property	🈚	1	lval -> bool
0	void	return undefined	🈚	1	any -> undef
null	await		🈚	null
13	**	exponentiation	R	2	(n, n) -> n
null	*, /, %	multiply, divide, remainder	L	2	(n, n) -> n
0	+, -	add, substract	L	2	(n, n) -> n
0	+	concatenate strings	L	2	(s, s) -> s
0	<<	shift left	L	2	(i, i) -> i
0	>>	shift right (sign extension)	L	2	(i, i) -> i
0	>>>	shift right (0 extension)	L	2	(i, i) -> i
0	< <= > >=	compare (number)	L	2	(n, n) -> b
0	< <= > >=	compare (string)	L	2	(s, s) -> b
0	instanceof	test object class	L	2	(o, f) -> b
0	in	test property existence	L	2	(a, o) -> b
0	==	equal (sloppy)	L	2	(a, a) -> b
0	!=	not equal (sloppy)	L	2	(a, a) -> b
0	===	equal (strict)	L	2	(a, a) -> b
0	!==	not equal (strict)	L	2	(a, a) -> b
0	&	bitwise AND	L	2	(i, i) -> i
0	^	bitwise XOR	L	2	(i, i) -> i
0	|	bitwise OR	L	2	(i, i) -> i
0	&&	logical AND	L	2	(a, a) -> a
0	||	logical OR	L	2	(a, a) -> a
0	??	nullish coalescing	L	2	(a, a) -> a
0	?:	ternary operator	R	3	(b, a, a) -> a
0	=	assignment	R	2	(lval, a) -> a
0	**= *= /= %= += -= &= ^= |= <<= >>= >>>=	operate/assign	R	2	(lval, a) -> a
0	,	return 2nd operand	L	2	(a, a) -> a