{"id":7306,"date":"2019-10-21T05:38:35","date_gmt":"2019-10-21T05:38:35","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=7306"},"modified":"2021-11-16T05:44:54","modified_gmt":"2021-11-16T05:44:54","slug":"complete-reference-guide-of-php-arrays","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/complete-reference-guide-of-php-arrays\/","title":{"rendered":"Complete reference guide of PHP Arrays!"},"content":{"rendered":"\n

What is PHP Arrays<\/h2>\n\n\n\n

Arrays are complex variables that allow us to store more than one value or a group of values under a single variable name. Let’s suppose you want to store colors in your PHP script. Storing the colors one by one in a variable could look something like this:<\/p>\n\n\n

<?php<\/span> \n$color1 = \"Red\"<\/span>;\n$color2 = \"Green\"<\/span>;\n$color3 = \"Blue\"<\/span>; \n?><\/span><\/span> <\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
But what, if you want to store the states or city names of a country in variables and this time this not just three may be hundred. It is quite hard, boring, and bad idea to store each city name in a separate variable. And here array comes into play. <\/p>\n\n\n\n
Types of Arrays in PHP<\/h2>\n\n\n\n
There are three types of arrays that you can create. These are:<\/p>\n\n\n\n
  • Indexed array<\/strong> \u2014 An array with a numeric key.<\/li>
  • Associative array<\/strong> \u2014 An array where each key has its own specific value.<\/li>
  • Multidimensional array<\/strong> \u2014 An array containing one or more arrays within itself.<\/li><\/ul>\n\n\n\n
    Indexed Arrays<\/h2>\n\n\n\n
    An indexed or numeric array stores each array element with a numeric index. The following examples shows two ways of creating an indexed array, the easiest way is:<\/p>\n\n\n
    <?php<\/span> \n\/\/ Define an indexed array <\/span>\n$colors = array<\/span>(\"Red\"<\/span>, \"Green\"<\/span>, \"Blue\"<\/span>); \n?><\/span><\/span> <\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
    Note:<\/strong> In an indexed or numeric array, the indexes are automatically assigned and start with 0, and the values can be any data type. <\/p><\/blockquote>\n\n\n\n
    Associative Arrays<\/h2>\n\n\n\n
    In an associative array, the keys assigned to values can be arbitrary and user defined strings. In the following example the array uses keys instead of index numbers:<\/p>\n\n\n
    <?php<\/span> \n\/\/ Define an associative array <\/span>\n$ages = array<\/span>(\"Peter\"<\/span>=>22<\/span>, \"Clark\"<\/span>=>32<\/span>, \"John\"<\/span>=>28<\/span>); \n\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
    Multidimensional Arrays<\/h2>\n\n\n\n
    The multidimensional array is an array in which each element can also be an array and each element in the sub-array can be an array or further contain array within itself and so on. An example of a multidimensional array will look something like this:<\/p>\n\n\n
    <?php<\/span>\n\/\/ Define a multidimensional array<\/span>\n$contacts = array<\/span>(\n    array<\/span>(\n        \"name\"<\/span> => \"Peter Parker\"<\/span>,\n        \"email\"<\/span> => \"peterparker@mail.com\"<\/span>,\n    ),\n    array<\/span>(\n        \"name\"<\/span> => \"Clark Kent\"<\/span>,\n        \"email\"<\/span> => \"clarkkent@mail.com\"<\/span>,\n    ),\n    array<\/span>(\n        \"name\"<\/span> => \"Harry Potter\"<\/span>,\n        \"email\"<\/span> => \"harrypotter@mail.com\"<\/span>,\n    )\n);\n\/\/ Access nested value<\/span>\necho<\/span> \"Peter Parker's Email-id is: \"<\/span> . $contacts[0<\/span>][\"email\"<\/span>];\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
    Viewing Array Structure and Values<\/h2>\n\n\n\n
    You can see the structure and values of any array by using one of two statements \u2014 var_dump()<\/code> or print_r()<\/code>. The print_r()<\/code> statement, however, gives somewhat less information. Consider the following example:<\/p>\n\n\n
    <?php<\/span>\n\/\/ Define array<\/span>\n$cities = array<\/span>(\"London\"<\/span>, \"Paris\"<\/span>, \"New York\"<\/span>);\n \n\/\/ Display the cities array<\/span>\nprint_r($cities);\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
    The print_r()<\/code> statement gives the following output:
    Array ( [0] => London [1] => Paris [2] => New York )
    This output shows the key and the value for each element in the array. To get more information, use the following statement: <\/p>\n\n\n
    <?php<\/span>\n\/\/ Define array<\/span>\n$cities = array<\/span>(\"London\"<\/span>, \"Paris\"<\/span>, \"New York\"<\/span>);\n \n\/\/ Display the cities array<\/span>\nvar_dump($cities);\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
    This var_dump()<\/code> statement gives the following output:
    array(3)\u2009{\u2009[0]=>\u2009string(6) “London” [1]=>\u2009string(5) “Paris” [2]=>\u2009string(8) “New\u2009York”\u2009}

     This output shows the data type of each element, such as a string of 6 characters, in addition to the key and value.  <\/p>\n\n\n