{"id":471,"date":"2021-03-17T09:17:26","date_gmt":"2021-03-17T09:17:26","guid":{"rendered":"https:\/\/phptutorial.net\/?page_id=471"},"modified":"2025-04-06T02:15:20","modified_gmt":"2025-04-06T02:15:20","slug":"php-named-arguments","status":"publish","type":"page","link":"https:\/\/www.phptutorial.net\/php-tutorial\/php-named-arguments\/","title":{"rendered":"PHP Named Arguments"},"content":{"rendered":"\n

Summary<\/strong>: in this tutorial, you will learn about PHP named arguments and how to use them effectively in your code.<\/p>\n\n\n\n

Introduction to the PHP named arguments #<\/a><\/h2>\n\n\n\n

Since PHP 8.0, you can use named arguments for functions. The named arguments allow you to pass arguments to a function<\/a> based on the parameter names<\/a> rather than the parameter positions.<\/p>\n\n\n\n

The following example defines a function that finds the position of the first occurrence of a substring in a string:<\/p>\n\n\n

<?php<\/span>\n\nfunction<\/span> find<\/span>($needle, $haystack)<\/span>\n<\/span>{\n    return<\/span> strpos($haystack, $needle);\n}    <\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
To call the find()<\/code> function, you pass the arguments based on the parameter positions like this:<\/p>\n\n\n
find('awesome'<\/span>, 'PHP is awesome!'<\/span>);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
In this case, $needle<\/code> is 'awesome'<\/code> and $haystack<\/code> is 'PHP is awesome!'<\/code>.<\/p>\n\n\n\n
However, the function call is not so clear. For example, you don’t know which argument is the needle and which argument is the haystack.<\/p>\n\n\n\n
Sometimes, you may accidentally make a mistake by passing the arguments in the wrong order. For example:<\/p>\n\n\n
find ( \n    'PHP is awesome!'<\/span>,\n    'awesome'<\/span>\n);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
This is buggy and very difficult to troubleshoot.<\/p>\n\n\n\n
find (\n    'awesome'<\/span>,        \/\/ needle<\/span>\n    'PHP is awesome!'<\/span> \/\/ haystack<\/span>\n);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
The comment makes the code more clear. However, it’s not robust.<\/p>\n\n\n\n
To improve this, PHP 8.0 introduced the named arguments that allow you to specify the parameter names when passing arguments:<\/p>\n\n\n
find (\n    needle : 'awesome'<\/span>,\n    haystack : 'PHP is awesome!'<\/span>\n);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Since you are using the parameter names, the positions are not necessary. For example, you can swap the parameters like this:<\/p>\n\n\n
find(\n    haystack :'PHP is awesome!'<\/span>,\n    needle : 'awesome'<\/span>\n);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
It should work correctly.<\/p>\n\n\n\n
Here’s the complete code:<\/p>\n\n\n
<?php<\/span>\n\nfunction<\/span> find<\/span>($needle, $haystack)<\/span>\n<\/span>{\n    return<\/span> strpos($haystack, $needle);\n}    \n\n\necho<\/span> find (\n    needle : 'awesome'<\/span>,\n    haystack : 'PHP is awesome!'<\/span>\n);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Skipping default arguments #<\/a><\/h2>\n\n\n\n
The following defines a function that creates an anchor element (<a><\/code>) from text, href, title, and target:<\/p>\n\n\n
<?php<\/span>\n\nfunction<\/span> create_anchor<\/span>(\n    $text,\n    $href = '#'<\/span>,\n    $title = ''<\/span>,\n    $target = '_self'<\/span>\n)<\/span>\n<\/span>{\n    $href = $href ? sprintf('href=\"%s\"'<\/span>, $href) : ''<\/span>;\n    $title = $title ? sprintf('title=\"%s\"'<\/span>, $title) : ''<\/span>;\n    $target = $target ? sprintf('target=\"%s\"'<\/span>, $target) : ''<\/span>;\n\n    return<\/span> \"<a $href $title $target>$text<\/a>\"<\/span>;\n}<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
$link = create_anchor(\n    'PHP Tutorial'<\/span>, \n    'https:\/\/phptutorial.net\/'<\/span>,\n    ''<\/span>,\n    '_blank'<\/span>\n);\n\necho<\/span> $link;<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Output:<\/p>\n\n\n
<a href=\"https:\/\/phptutorial.net\/\"<\/span>  target=\"_blank\"<\/span>>PHP Tutorial<\/a><\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
In this example, you must pass space (”) to the third argument. Using the named arguments, you don’t have to specify all the defaults. For example:<\/p>\n\n\n
 $link = create_anchor(\n    text : 'PHP Tutorial'<\/span>, \n    href : 'https:\/\/phptutorial.net\/'<\/span>,\n    target: '_blank'<\/span>\n);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Heres’ the complete code:<\/p>\n\n\n
<?php<\/span>\n\nfunction<\/span> create_anchor<\/span>(\n    $text,\n    $href = '#'<\/span>,\n    $title = ''<\/span>,\n    $target = '_self'<\/span>\n)<\/span>\n<\/span>{\n    $href = $href ? sprintf('href=\"%s\"'<\/span>, $href) : ''<\/span>;\n    $title = $title ? sprintf('title=\"%s\"'<\/span>, $title) : ''<\/span>;\n    $target = $target ? sprintf('target=\"%s\"'<\/span>, $target) : ''<\/span>;\n\n    return<\/span> \"<a $href $title $target>$text<\/a>\"<\/span>;\n}\n\n\n $link = create_anchor(\n    text : 'PHP Tutorial'<\/span>, \n    href : 'https:\/\/phptutorial.net\/'<\/span>,\n    target: '_blank'<\/span>\n);\n\necho<\/span> $link;<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
Mixing named arguments with positional arguments #<\/a><\/h2>\n\n\n\n
PHP allows you to call a function using both positional and named arguments. And you need to place the named arguments after positional arguments. For example:<\/p>\n\n\n
$link = create_anchor(\n    'PHP Tutorial'<\/span>, \n    'https:\/\/phptutorial.net\/'<\/span>,\n     target: '_blank'<\/span>\n);<\/code><\/span>Code language:<\/span> PHP<\/span> (<\/span>php<\/span>)<\/span><\/small><\/pre>\n\n\n
In this example:<\/p>\n\n\n\n
Try it<\/a><\/p>\n\n\n\n
To create a link with the target is _blank<\/code>, you must specify all the default arguments<\/a> until the one you want to change. For example:<\/p>\n\n\n
Try it<\/a><\/p>\n\n\n\n
To avoid this, you may add comments<\/a> to the arguments like this:<\/p>\n\n\n