What is the performance difference between foreach and for in php?

What is the performance difference between foreach and for in php? The following article will compare the performance of for and foreach in PHP and introduce the difference between foreach and for. It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.

Performance comparison between for and foreach in php

Generally speaking, it can only be seen if the database exceeds hundreds of thousands. Faster or slower, if it is less than 100,000 cycles, there is no need to test. PHP recommends using foreach.

When looping a numeric array, for needs to count($arr) to calculate the array length in advance, and the auto-increment variable $i needs to be introduced. Each loop must perform conditional judgment $i

When foreach loops the array, the pointer will automatically point to the next element. There is no need to calculate the array length, there is no conditional judgment and auto-increment variables, and there is no hash operation when calling the element, so the performance is definitely better than for and while high.

In addition, for and while are powerless for associative arrays with key-value mappings. Therefore, when traversing an array, foreach is preferred.

foreach is also my favorite keyword in PHP because it is really powerful. array_map/array_filter/array_walk traverses the array in the same way as foreach, but needs to execute a callback function, so it is slower than foreach.

For more related knowledge, please pay attention to PHP Chinese website! !

The above is the detailed content of What is the performance difference between foreach and for in php?. For more information, please follow other related articles on the PHP Chinese website!