Unary Operators: Unary "+" operator, in depth
converts its operand to the Number type
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Unary "+" operator
- converts its operand to the Number type
GIVEN simple operands
- converting
undefined returns NaN
- converting
null returns +0
- converting
true returns 1
- converting
false returns +0
- converting
false does NOT return -0
- a number does NOT get converted
WHEN the operand is a string
- AND its not numeric THEN it converts to
NaN
- AND even when it starts with a number THEN it converts to
NaN
- AND it is the word "Infinity" THEN it returns
Infinity
- AND it is a "-" and the word "Infinity" THEN it returns
-Infinity
- AND it is "+0" THEN it does NOT return
-0
- AND it starts with a decimal point THEN it converts the string to the according number
- AND it contains an exponential value THEN it converts it to the according number
- AND it starts with a hexadecimal number THEN it returns the according decimal number
- AND it is an exponential number THEN it returns it as type Number
- AND it has any kind of spaces surrounding it THEN those are ignored and the number is returned
GIVEN complex operands
- WHEN the operand is an array THEN its string`s value is returned as number
- WHEN the operand is a Date THEN the unix timestamp is returned
WHEN the operand is an object
- AND its an empty object literal THEN it converts to
NaN
- AND it has one prop
{x: 0} THEN it converts to NaN
- AND its and empty class THEN it converts to
NaN
- AND its a class with a
valueOf method THEN its result is used
- AND its a class with a
toString method THEN its result is used
- AND its a class with
valueOf() and toString() THEN valueOfs value is used