foreword
In JavaScript, we can be divided into two types:
basic type;
complex type;
The difference between the two types is: the storage location is different.
1. Basic type
Undefined, Null, Number, Boolean, String and Symbol (symbol, new in es6)
2. Complex types
Object
In ECMAScript, all values can be represented by one of the above seven data types.
What we are talking about today is Number in the basic data type
Number
The most common integer type format for values is decimal, and octal (starting with zero), hexadecimal (starting with 0x) can also be set
1. Decimal
Decimal integers are the most basic numeric literals, which can be written directly:
let Num = 22 // 10进制的222. Octal
The prefix is 0, and then the corresponding octal number is connected, usually 0~7.
If the number in the literal exceeds the expected range, the leading 0 will be ignored, and the following sequence of numbers will be treated as a decimal number.
let num1 = 026 // 8进制的22
let num2 = 081 // 无效 变为10进制How to convert octal to decimal:
Hundreds digit × 8 to the 2nd power + tens digit × 8 to the 1st power + units digit × 8 to the 0th power = decimal
For example: num1=026; converted to decimal is: 0 × 8² + 2 × 8¹ + 6 × 8º = 22
- Except 0, any number raised to the power of 0 is equal to 1
- Octal values in ECMAScript 2015 or ES6 are represented by the prefix 0o; in strict mode, the prefix 0 is considered a syntax error, and if you want to represent an octal value, you should use the prefix 0o
3. Hexadecimal
Prefixed with 0x (case sensitive), hexadecimal digits are 0 ~ 9 and A ~ F.
The binary numbers represented by ABCDEF are: 10, 11, 12, 13, 14, 15
let Num1 = 0x1A //16进制的26Calculation method of converting hexadecimal to decimal:
Hundreds digit × 16 to the 2nd power + tens digit × 16 to the 1st power + units digit × 16 to the 0th power = decimal
For example: Num1=0x1A; converted to decimal is: 1 × 16¹ + 10 × 16º = 16 + 10= 26
4. Binary
The value is only 0 and 1, and the representation of binary literals is added in es6, starting with 0b
let num5 = 0b101 //2进制的5
let num6 = 0b111001 //2进制的57Binary to decimal calculation method:
... Hundreds digit × 2 to the 2nd power + tens digit × 2 to the 1st power + units digit × 2 to the 0th power = decimal
Such as: num6=0b111001; converted to decimal is: 57
A base converter is recommended here, which can be converted into the base you want