Over a million developers have joined DZone.

Step-by-step Logic Finding Prime numbers with PHP

· Web Dev Zone

A Prime numbers are all integers(number) that can be divided evenly only by 1 AND itself.
And it must be a whole number greater than 1. 

  2           3      
 /   \        /  \     ...................
1   2      1  3

Logic in Program

Prime Logic

Take a look above, the green numbers indicate that each prime number has exactly 2 (two) divisors. 1 and itself. From this simple logic, we can easily code it . Take a look again in Snippet above

Notes: This example is just for those who are new to this
function prime($n){

      //all numbers that will be evaluated as prime       

prime(20);  //find the Prime for 1-20 range

The best of DZone straight to your inbox.

Please provide a valid email address.

Thanks for subscribing!

Awesome! Check your inbox to verify your email so you can start receiving the latest in tech news and resources.

{{ parent.title || parent.header.title}}

{{ parent.tldr }}

{{ parent.urlSource.name }}