Implicit conversion:
Scene - mathematical operators: + - * /
Rules:
+: when the character appears on either side, "+" will be converted into numeric type character type, representative of the splice case +
-, *, /: emergence when purely numeric characters, converted into a numerical type of treatment, non-numeric type occurs, there will be "NaN"
Scene - relational operators:> <!> = <= = == ===
rule:
when only one side is purely numeric characters, converted into a numerical comparison
, when both sides of all numeric characters, the string comparison will follow Comparative rule (bit-wise comparison, the results obtained, the comparison stops)
==: if the character type converted to numeric types, the comparison is a value
===: if a character is not the type conversion, comparing the values and data types, congruent
Scene --if statement:
Rules:
0, "", null, undefined, NaN if in the () are converted to false
Cast:
Character transfer value:
parseInt (): from left to right conversion, you can turn turn, can not be transferred stop; if you can not turn the first direct NaN; does not recognize decimal point.
parseFloat (): equivalent to the parseInt, while the decimal point may be identified
Math.round (): Conversion strictly, any non-numeric characters are not allowed, otherwise NaN3; rounded to the nearest integer
Number (): Conversion strictly, does not allow any non- numeric characters, or NaN3; direct conversion
-, *, /: using a mathematical operator implicit conversion, the values into character
Numerical character turn:
toString (): to convert into a direct numerical character
toFixed (): direct conversion parameter decimal place reserved
+: using a mathematical operator implicit conversion, a null character + is connected
to other types of conversions:
Use +, -, *, / p true, false, null conversion can be obtained, true is 1, false is 0, null 0