Base conversion in PHP

Binary system

Four kinds

1. Binary system: 0,1, full 2 ​​enters 1.

In golang, binary cannot be used directly to represent an integer, it follows the characteristics of c.

2. Decimal: 0-9, 10 to 10.
3. Octal: 0-7, full 8-digit 1. It starts with the number 0.
4. Hexadecimal: 0-9 and A-F, full 16 in 1. It starts with 0x or 0X. A-F here are not case sensitive.

package main
import "fmt"
func main() {
    var i int = 5
    //二进制
    fmt.Printf("%b \n",i)

    var j int = 011 // 011=>8+1 = 9
    //八进制
    fmt.Println("j=",j)

    var k int = 0x11 //0x11 => 16+1 =17
    //十六进制 0x或者0X开头
    fmt.Println("k=",k)
}
//101
//j= 9
//k= 17

Base Illustration

##1. Convert other bases to decimal

Binary to decimal
1. Octal to decimal
2. Hexadecimal to decimal

Binary to decimal

Rule: from lowest Starting with the digit (on the right), extract the number on each digit, multiply it by 2 raised to the (digit order - 1) power and then sum it up

Case: 1011= $1
2^3 0 2^2 12^1 12^0$=8 2 1 = 11

Octal to decimal

Rule: Starting from the lowest digit (the one on the right), Extract the number in each digit, multiply it by 8 raised to the power of (digit order -1) and sum it up

Case: 0123 = $1
8^2 28^1 3*8^ 0$=64 16 3 = 83

Hexadecimal to decimal

Rule: Starting from the lowest digit (the one on the right), extract the number in each digit and multiply by 16 of (place-1) power and then sum up

Case: 0x34A = $10
16^0 416^1 3*16^2$= 10 64 768 = 842

2. Convert decimal to other bases

Convert decimal to binary
1. Convert decimal to octal
2. Convert decimal to hexadecimal

Decimal to binary

Rules: Keep dividing the number by 2 until the quotient is 0, and then reverse the remainder obtained at each step, which is the corresponding binary

case: 56= 111000

Convert decimal to octal

Rule: Keep dividing the number by 8 until the quotient is 0, and then reverse the remainder obtained at each step, which is the corresponding octal number

Case: 156=0234

Convert decimal to hexadecimal

Rule: Keep dividing the number by 16 until the quotient is 0, then reverse the remainder obtained at each step to get the corresponding hexadecimal System

Case: 356= 0x164

3. Binary to other system

Binary to octal
1. Binary to hexadecimal

Convert binary to octal

Rule: Convert each binary number into a group of three digits (combining from the low bit--

right!), and convert it to the corresponding octal numberCase: 11010101 = 11/010/101 = 324 = 0324

Binary to hexadecimal

Rule: Binary numbers are grouped into groups of four digits (starting from the low bit -

Right!), convert it to the corresponding hexadecimal numberCase: 11010101= 1101/0101 = 13/5 = D5 = 0xD5

4. Octal, ten Convert hexadecimal to binary

Convert octal to binary
1. Convert hexadecimal to binary

Convert octal to binary

Rule: Convert hexadecimal to binary Each digit of the octal number (combined starting from the low bit -

on the right ! ), convert it into a corresponding 3-digit binary numberCase: 0237= 10/011/111 = 10011111

Hexadecimal to binary

Rule: Convert ten Each digit of the hexadecimal number (combined starting from the low bit--

right side!) can be converted into a corresponding 4-digit binary numberCase: 0x237= 10/0011/0111 = 1000110111

It’s a bit confusing, let’s summarize it again

---

hexadecimal summary

1: Type: 2 , 8, 10, 16

2: Specific composition

1. 2:0, 1
2. 8:0-7
3. 10：0-9
##16:0-9、A、B、C、 D, E, F

3: Convert other bases to decimal

times the power of the base to be converted (bit-1) Then sum

4: convert decimal to other bases

The converted number is divided by the number to be converted until the quotient is 0, and then each Reverse the remainder obtained in this step

5: Convert binary to other bases

Convert to octal, starting from the right, divide every three digits

Convert to hexadecimal, start from the right, divide every four digits into 6:

Convert octal and hexadecimal to binary

Convert octal, start from the right, Every three digits are divided into Hexadecimal conversion, starting from the right, every four digits are divided into

For more PHP related technical articles, please visit the

PHP Tutorial

column to learn !

The above is the detailed content of Base conversion in PHP. For more information, please follow other related articles on the PHP Chinese website!