Number - Number.isFinite() && Number.isNaN()

Number.isFinite()

Value is used to check whether a limited (finite), whether there is a finite number (finite number), i.e. notInfinity

If the parameter type is not a value, Number.isFiniteshall be returnedfalse

Number.isFinite(NaN); // false
Number.isFinite(Infinity); // false
Number.isFinite(-Infinity); // false
Number.isFinite('foo'); // false
Number.isFinite('15'); // false
Number.isFinite(true); // false

　　

Number.isFinite(0);         // true
Number.isFinite(2e64);      // true
Number.isFinite(0.8); // true

　　Number.isNaN()

Used to check whether a value NaN.

If the parameter type is not NaN, Number.isNaNshall be returned false.

　　

        isNaN (to true); // to false 
        isNaN (null); // to false 
        isNaN (37 [); // to false 
        // strings 
        isNaN ( "37 ["); // to false: the value may be converted into 37 [ 
        isNaN ( "37.37") ; // false: the value may be converted into 37.37 
        isNaN ( ""); // false: the empty string is converted into 0 
        isNaN ( ""); // false: the string is converted into the spaces 0 
        // a dates 
        isNaN (new Date ()); // false

　　

        isNaN (NaN3); // to true 
        isNaN (undefined); // to true 
        isNaN ({}); // to true 
        isNaN ( "37,5"); // to true 
        isNaN (new new a Date () toString ().); / / to true 
        isNaN ( "blabla") // to true: "blabla" // value that can not be converted into numerical fails, the return NaN3 
        Number.isNaN (. 9 / NaN3) to true // 
        Number.isNaN ( 'to true' / 0) / / to true 
        Number.isNaN ( 'to true' / 'to true') to true //