The difference between ++i and i++

1. Usage of ++i (take a=++i, i=2 as an example)
First add 1 to the i value (that is, i=i+1), and then assign it to variable a (that is, a=i ),
Then the final a value is equal to 3 and the i value is equal to 3.
So a=++i is equivalent to i=i+1, a=i
2, the usage of i++ (take a=i++, i=2 as an example)
First assign the i value to the variable a (that is, a= i ), then add 1 to the i value (that is, i=i+1),
Then the final a value is equal to 2 and the i value is equal to 3.
So a=i++ is equivalent to a=i, i=i+1
3, ++i and i++
a=++i is equivalent to i++, a=i
a=i++ is equivalent to a=i, i++
4 , ++i and i++ are equivalent to i=i+1
when used alone. If assigned to a new variable, ++i first adds 1 to the i value, and i++ first assigns i to the new variable.

The above has introduced the difference between ++i and i++, including some aspects. I hope it will be helpful to friends who are interested in PHP tutorials.