Javascript Number - 10 Methods and 5 Properties (Reference)
Javascript
1
The Number in Javascript is a primitive data type that represents a number. The Number object is a wrapper around the primitive number type.
Number Methods:
Number Properties:
isFinite()
Determines whether a value is a finite number.
Number.isFinite(123); //true
Number.isFinite(-1.23); //true
Number.isFinite(5 - 2); //true
Number.isFinite(0); //true
Number.isFinite("123"); //false
Number.isFinite("Hello"); //false
Number.isFinite("2005/12/12"); //false
Number.isFinite(Infinity); //false
Number.isFinite(-Infinity); //false
Number.isFinite(0 / 0); //false
isInteger()
Determines whether a value an integer.
Number.isInteger(123); //true
Number.isInteger(-123); //true
Number.isInteger(5 - 2); //true
Number.isInteger(0); //true
Number.isInteger(0.5); //false
Number.isInteger("123"); //false
Number.isInteger(false); //false
Number.isInteger(Infinity); //false
Number.isInteger(-Infinity); //false
Number.isInteger(0 / 0); //false
isSafeInteger()
Determines whether a value an IEEE-754 double precision number (all integers from (253 - 1) to -(253 - 1)).
Number.isSafeInteger(123); //true
Number.isSafeInteger(-123); //true
Number.isSafeInteger(5 - 2); //true
Number.isSafeInteger(0); //true
Number.isSafeInteger(0.5); //false
Number.isSafeInteger(Math.pow(2, 53)); //false
Number.isSafeInteger(Math.pow(2, 53) - 1); //true
Number.isSafeInteger("123"); //false
Number.isSafeInteger(false); //false
Number.isSafeInteger(Infinity); //false
Number.isSafeInteger(-Infinity); //false
Number.isSafeInteger(0 / 0); //false
isNaN()
Determines whether a value is NaN (Not-A-Number).
Number.isNaN(123); //false
Number.isNaN(-1.23); //false
Number.isNaN(5 - 2); //false
Number.isNaN(0); //false
Number.isNaN("123"); //false
Number.isNaN("Hello"); //false
Number.isNaN("2005/12/12"); //false
Number.isNaN(""); //false
Number.isNaN(true); //false
Number.isNaN(undefined); //false
Number.isNaN("NaN"); //false
Number.isNaN(NaN); //true
Number.isNaN(0 / 0); //true
toExponential()
The toExponential() method formats a number in exponential notation.
Var num = 5.56789;
num.toExponential();
// 5.56789e+0
var num = 5.56789;
num.toExponential(1);
// 5.6e+0
toFixed()
It converts to a specified number of decimals.
Var num = 5.56789;
num.toFixed(2);
// 5.57
toPrecision()
Formats a number to a specified length.
Var num = 13.3714;
num.toPrecision(2);
// 13
toLocaleString()
It converts using a local language format.
var x = 1000000;
x.toLocaleString("fi-FI");
// 1 000 000
toString()
The toString() method converts a number to a string.
var num = 100;
num.toString();
// 100
valueOf()
The valueOf() method returns the primitive value of a Number object. Basically, it returns the number itself.
var num = 100;
num.valueOf();
// 100
NaN
The NaN property is a property of the Number object that represents Not-A-Number.
var x = Number.NaN;
MAX_VALUE
The MAX_VALUE property is a property of the Number object that represents the maximum value a number can have.
var x = Number.MAX_VALUE;
// 1.7976931348623157e+308
MIN_VALUE
The MIN_VALUE property is a property of the Number object that represents the minimum value a number can have.
var x = Number.MIN_VALUE;
// 5e-324
NEGATIVE_INFINITY
The NEGATIVE_INFINITY property is a property of the Number object that represents negative infinity.
var x = Number.NEGATIVE_INFINITY;
// -Infinity
POSITIVE_INFINITY
The POSITIVE_INFINITY property is a property of the Number object that represents positive infinity.
var x = Number.POSITIVE_INFINITY;
// Infinity
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