What requirements does JavaScript have for base numbers?

Base numbers play a very important role in computer science. They are the basis for computers to process and represent numbers. In JavaScript, we can use different bases to represent numbers, including binary, octal and hexadecimal. But JavaScript has some requirements and restrictions on base numbers. In this article, we will discuss the requirements and limitations of JavaScript for base numbers.

First of all, let us introduce the concept of different base numbers.

Binary is a base system based on the number 2. It uses only two numbers 0 and 1 to represent numbers.

Octal is a base system based on the number 8. It uses the numbers 0-7 to represent numbers.

The decimal system is the number system we usually use. It is based on the number 10 and uses the numbers 0-9 to represent numbers.

Hexadecimal is a base system based on the number 16. It uses the numbers 0-9 and the letters A-F to represent numbers.

In JavaScript, we can use different base numbers to represent numbers. Here are some examples:

Binary number: 0b1010 (decimal: 10)

Octal number: 0o12 (decimal: 10)

Hexadecimal number: 0xA (decimal :10)

However, JavaScript has some requirements and restrictions on base numbers. Here are some important requirements and limitations:

1. Number types in JavaScript are signed 64-bit floating point numbers. This means that JavaScript can represent very large numbers, but there is also a loss of precision. Therefore, special care should be taken when dealing with large numbers.
2. When using hexadecimal, letters in JavaScript are not case-sensitive. For example, 0xa and 0xA are the same.
3. When using octal, if you use the numbers 8 or 9, they will be treated as decimal numbers. Therefore, care should be taken to avoid using the numbers 8 and 9.
4. If you add a number other than 0 and 1 when using binary, it will be treated as a decimal number.
5. When using base numbers, their base type should be clearly specified. If no type is specified, JavaScript will default to decimal.

Here are some examples:

// Decimal
const decimalNumber = 10;

// Binary
const binaryNumber = 0b1010;

// Octal
const octalNumber = 0o12;

// Hexadecimal
const hexadecimalNumber = 0xA;

In JavaScript, we can use parseInt( ) function parses a string into a number. This function can parse strings into numbers in different bases, for example:

// Parse binary numbers
const binaryNumber = parseInt('1010', 2);

// Parse octal numbers
const octalNumber = parseInt('12', 8);

// Parse hexadecimal numbers
const hexadecimalNumber = parseInt('A', 16);

In this example, the parseInt() function can accept a string and a numeric parameter representing the base. If no base parameter is specified, it defaults to decimal.

In short, JavaScript has some requirements and restrictions on base numbers. To use base numbers correctly, you should be aware of these requirements and limitations, paying special attention to the loss of precision and the specification of the base type.

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