What does '>>' mean in php

In PHP, ">>" is the bit right shift operator. It shifts the binary representation of a number to the right by a certain number of bits and fills the empty bits on the left with zeros.

For example, if we shift the number 10 (1010 in binary) one place to the right, we will get 5 (0101 in binary):

$number = 10;
$shifted = $number >> 1;
echo $shifted; // 输出 5

In this example, we will $number The value of changes from 10 to 5. This is because we shifted the first bit of its binary representation one position to the right, ending up with 0101. This is equivalent to dividing it by 2^1 (which is 2), giving you 5.

We can also obtain different results by shifting the number to the right by multiple digits. For example, if we shift the number 10 two places to the right, we get 2 (0010 in binary):

$number = 10;
$shifted = $number >> 2;
echo $shifted; // 输出 2

In this case, we shift the first two bits of the binary representation of $number to the right Moving around, you get 0010, which is equivalent to dividing it by 2^2 (which is 4), giving you 2.

We can also use bitwise operators to shift bits to the left, which is called bit left shift. Left shift moves a binary number to the left by a certain number of bits and adds zeros to the empty bits on the right.

For example, if we shift the number 2 one position to the left, we will get 4 (0100 in binary):

$number = 2;
$shifted = $number << 1;
echo $shifted; // 输出 4

In this example, we start with the first bit of the binary representation , shifted one position to the left and added a zero to the right, giving us 0100, which is equivalent to multiplying it by 2, giving us 4.

In short, ">>" has a bit right shift function in PHP, and we can use it to move binary numbers to the right. It allows us to perform some mathematical calculations and bit operations in a more efficient and simple way.

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