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Numbers in JavaScript

JavaScript provides us with double-precision floating-point number to deal with the numbers in the code. You don’t need to specifically write int or float for declaring integer or floating values, unlike other programming languages.

let totalPlayer=10;

console.log(totalPlayer);


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let totalPlayer=10;
console.log(totalPlayer);

`+` Operator with Numbers:

+ operator is used in two ways with the number data type.

Addition: + is used for addition when both the operands are numbers, for example.

let firstNumber = 10;

let secondNumber = 20;

let total = firstNumber + secondNumber;

console.log(total);


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let firstNumber = 10;
let secondNumber = 20;
let total = firstNumber + secondNumber;
console.log(total);

Concatenation:
When one operand is a number while the other is a string, the + operator concatenate them together, for example.

let company = 'Robotech ';

let version = 10;

let newLaunch = company + version;

console.log(newLaunch);


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let  company = 'Robotech ';
let  version = 10;
let  newLaunch = company + version;
console.log(newLaunch);

JavaScript NaN and Infinity:

In JavaScript, the number datatype has some exceptions which are called “Special Numeric Values”. The exceptions are:

NaN:
NaN stands for Not a Number. NaN, in JavaScript, is a keyword that is used to check whether the value or variable is not a number.
We get NaN as a result when we perform arithmetic operations other than + between a numeric value and a string value, for example.

let numberOfStudent = 20;

let greeting = 'Hello';

let total = numberOfStudent - greeting;

console.log(total);


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let  numberOfStudent = 20;
let  greeting = 'Hello';
let  total = numberOfStudent - greeting;
console.log(total);

Infinity:
We get Infinity or -Infinity, in JavaScript, if the result of a calculation exceeds the largest possible number or the smallest possible number respectively, for example.

console.log("2 / 0 :", 2 / 0)

console.log("-2 / 0 :", -2 / 0)


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console.log("2 / 0  :", 2 / 0)
console.log("-2 / 0 :", -2 / 0)

In JavaScript, you can use the isFinite() function to check whether a value or variable is Finite or not, for example.

let score = 123;

let status = 'Test';

console.log(isFinite(score));

console.log(isFinite(status));


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let score = 123;
let status = 'Test';
console.log(isFinite(score));
console.log(isFinite(status));

Note:
If isNaN() returns true, it means that the data type is not a number.

let name = 'Bob';

console.log(isNaN(name));


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let name = 'Bob';
console.log(isNaN(name));

Compito

Swipe to start coding

A variable named comment with the assigned value of "hello123" has been given to you. Your task is to check and print whether the comment variable is a number or not as well as whether it is Finite or not.