如何将字符串转换为int并逐字符地将它们拆分为另一个数组

Question

Using this function,prt_pattern("341","0"), to print out

 0 
00 
00 
000

I'm stuck at converting "341" into integer and store it each number the following was the result i wanted

array[0] = 3
array[1] = 4
array[2] = 1

The flow I'm going to plan for this function is, convert string into int and store it by character, and then find the highest value. After that using 2 for loop, 1st for loop is loop from largest number to 1 and 2nd loop is for looping the number if 4 = 4, print 0 else print " " and value at array[1] -= 1.

Hope anyone can help me with this.

Answer 1

This should work. First I create an array of each number inside the string (cast to integer), then find the highest number from it using the max function.

<?php
$array = (function ($str): array {
    $a = [];
    $strlen = strlen($str);
    for($i = 0; $i < $strlen; $i++) {
        $a[] = (int) $str[$i];
    }
    return $a;
})("3429");


var_dump($array);

/**
array(4) {
  [0]=>
  int(3)
  [1]=>
  int(4)
  [2]=>
  int(2)
  [3]=>
  int(9)
}
**/

var_dump(max($array)); //int(9)

Test it online here : http://sandbox.onlinephpfunctions.com/code/2e3446d4475c3d69215857ed33a2c1f94f628e0b

edit

As Barmar pointed out in the comments, its way easier to use PHPs function str_split like so:

$array = str_split("3429");

Which will create an array just like previous mentioned.

(I feel silly for not thinking of that function.)