This paper summarizes the meaning, generation and judging methods of Nan and INF in C language. Nan in the C language means not a number, which is equivalent to #IND: indeterminate (Windows) generates:An undefined operation was performed on a
Nan is ' not a number ', is not a digit, so what is Nan exactly? In JavaScript, there are 6 big data types, including String,number,boolean,undefined,null and object, and for JS, integers and floating-point numbers are collectively referred to as
1. Misunderstanding correction of attribute NanNan (not a number) defines a non-numeric special value in the list of numbers, and it has an object that does not have the value of any non-numeric type equal to Nan, only if the arithmetic operation
1. Judge whether each other is equalfunction Btnclick () {alert (null = = NULL);//true alert (undefined==undefined);//true alert (Nan==nan);//false}Summarize:(1) Two null is equal(2) Two undefined are equal(3) Two Nan is unequalfunction Btnclick () {
Strictly judge NaN in JavaScript, while javascript judges nan
I also encountered this question on FreeCodeCamp:
Delete all values in the array.
In JavaScript, the false values include false, null, 0, "", undefined, and NaN.
For NaN judgment, JS
1.NaNIn JavaScript, Nan represents "not a number". This value is returned primarily when parsing a string error:
Copy Code code as follows:
> Number ("xyz")
Nannan
The name is "not a number", but it can also be said not to
1. NaN
In JavaScript, NaN indicates "not a number". This value is returned when an error occurs in parsing the string:Copy codeThe Code is as follows:> Number ("xyz ")NaNNaN
The name is "not a number", but it can be said that it is not a number:Copy
NaN is an abbreviation for not a number. It is a numeric type value, typically in a floating-point calculation, that represents a value that is undefined or cannot be represented. Also, you cannot use the equality operator (= =) to check NaN. In the
(1) The following three cases typeof return type is undefined--When the variable is not initialized--When a variable is not defined--When the function has no explicit return value (undefined is returned when the function has no return value)(2) Null
I believe many beginner JavaScript will have this idea: why JavaScript is null and undefined, relative to C, C + +, Java, they are all just null, why JavaScript is differentOne, historical reasons The web search learned that,when JavaScript was born
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