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Step-by-step Logic Finding Prime numbers with PHP

· Web Dev Zone

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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

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