Is it possible to implement the algorithm in PHP in another PL?

Question

Programming

Good afternoon!
I continue to study programming (in particular, the PHP language), in order to understand the algorithms, I decided to take this approach for myself:
1. from the book "128 PHP recipes" we take any algorithm
2. I chose the fourth algorithm "Displaying a multiple of N"
To determine the number of a multiple of N, you can take advantage of the possibility of obtaining the remainder of the division. If when dividing a number by N, the remainder is zero, then the number is a multiple. It is only necessary to add one more condition - checking the number for zero, since 0 / N \u003d 0, without a remainder.

$n = 3;

for ($i=0; $i<10; $i++)
{
  if ((($i%$n) == 0) AND ($i != 0))
  {
    echo $i . "<br/>";
  }
}

3. I will try to understand the operation of this algorithm and implement it in another programming language, for example, in C
Question: how effective will this approach be in training?
Thank you!

Answer 1

How effective will this teaching approach be?

To learn a particular language, the profit will most likely be negative, but the language is just a tool, it does not need to be learned, it must be used. And you need to study programming in general. And here the profit is debatable, but if you try to optimize the algorithm using the means of each of the languages, there will be a profit.
For starters, I would improve readability:

$n = 3;
for ($i = 0; $i < 10; $i++)
{
  if ((($i % $n) == 0) AND ($i != 0))
  {
    echo $i . "<br/>";
  }
}

Now let's optimize in PHP itself:

$n = 3;
for ($i = 0; $i < 10; $i += $n)
{
  if ($i == 0) continue;
  echo $i . "<br/>";
}

Let's try to rewrite to js first:

const n = 3;
for(let i = 0; i < 10; i++) {
  if((i % n === 0) && (i !== 0)) {
    console.log(i + '<br/>');
  }
}

Note that if the code is similar, the result is different, in addition to the numbers separated by line breaks. But you can rewrite it in another way:<br/>

const n = 3;
console.log(Array.from({length: 9}, (_, i) => i + 1).filter(i => i % n === 0).join('<br/>'));

Try a strongly typed language like Rust:

fn main() {
    const N: i32 = 3;
    for i in (1..10).filter(|i| i % N == 0) {
        print!("{}<br/>", i);
    }
}

Already in the second language we see that not only through if you can weed out unnecessary values.
Maybe try something lower level like C:

#include <stdio.h>

int main() {
    int n = 3;
    for(int i = 0; i < 10; i += n) {
        if(!i) continue;
        printf("%d<br/>", i);
    }
    return 0;
}

I note that there is no bool type in C, so you can use a condition like (!i) to check for 0
Finally...

.TXT:
  .string	"%d<br/>"
  .text
  .globl	main
  .type	main, @function
main:
  .cfi_startproc
  pushq	%rbp
  .cfi_def_cfa_offset 16
  .cfi_offset 6, -16
  movq	%rsp, %rbp
  .cfi_def_cfa_register 6
  subq	$16, %rsp
  movl	$3, -8(%rbp)
  movl	$0, -4(%rbp)
  jmp	.LOOP_COND
.LOOP_BODY:
  cmpl	$0, -4(%rbp)
  je	.LOOP_NEXT
  movl	-4(%rbp), %eax
  movl	%eax, %esi
  leaq	.TXT(%rip), %rdi
  movl	$0, %eax
  call	[email protected]
  jmp	.LOOP_NEXT
.LOOP_NEXT:
  movl	-8(%rbp), %eax
  addl	%eax, -4(%rbp)
.LOOP_COND:
  cmpl	$9, -4(%rbp)
  jle	.LOOP_BODY
  movl	$0, %eax
  leave
  .cfi_def_cfa 7, 8
  ret
  .cfi_endproc

so for the overall development

Answer 2

Well, here it is in JS:

var n = 3;
for(let i=0;i<10;i++){
    if(((i%n)==0) && (i!=0)){
        console.log(i);
    }
}

Did it help?

Answer 3

Understanding the logic of the algorithm will decrease by 50% EXACTLY!
50% - that you will understand a new language.
50% - that you will understand this language (PHP)
50% - that you will understand the logic of the algorithm itself.
That is, the effectiveness of teaching the current language will be: (50+50+50)/2 = 75%