How to find specific elements after PHP array is shuffled?

Methods to find specific elements in a shuffled PHP array are: iterate through the array and compare the elements. Use the array_search() function to find keys. Use the in_array() function to check for existence.

How to find specific elements in a shuffled PHP array

Introduction

In PHP, arrays essentially store elements in insertion order. However, sometimes we need to shuffle the order of an array so that its elements are randomly arranged. This is usually done for security or privacy purposes.

When the order of an array is disrupted, finding a specific element may become difficult. This article will show you how to efficiently find specific elements in a shuffled PHP array.

Method

To find specific elements in a shuffled array, you can use the following method:

1. Traverse the array:

The simplest way is to use foreach to loop through the array and compare each element to see if it matches the target element.

function find_in_shuffled_array($arr, $target) {
  foreach ($arr as $key => $value) {
    if ($value === $target) {
      return $key;
    }
  }
  return -1;
}

2. Use the array_search() function:

PHP’s built-in array_search() function can quickly Searches an array for a given value and returns its key (index).

function find_in_shuffled_array($arr, $target) {
  // strict 可以防止类型松散匹配
  return array_search($target, $arr, true);
}

3. Use the in_array() function:

in_array() The function checks whether the given value exists in the array value and returns a Boolean value. It returns true if the target element is found, otherwise it returns false.

function find_in_shuffled_array($arr, $target) {
  // strict 可以防止类型松散匹配
  if (in_array($target, $arr, true)) {
    return true;
  } else {
    return false;
  }
}

Practical case

Suppose we have a shuffled array of integers:

$arr = [3, 1, 5, 7, 2, 4];

To find the number in the array5, we can use the following code:

$key = find_in_shuffled_array($arr, 5);

if ($key !== -1) {
  echo "5 found at position {$key}\n";
} else {
  echo "5 not found in the array\n";
}

Output:

5 found at position 2

The above is the detailed content of How to find specific elements after PHP array is shuffled?. For more information, please follow other related articles on the PHP Chinese website!