How to convert php array to query string

When we need to convert a PHP array into a query string, we can use PHP's http_build_query() function. This function accepts an array as parameter and returns a query string.

Sample code:

$data = array(
    'name' => 'John',
    'age' => 30,
    'city' => 'New York'
);

$query_string = http_build_query($data);

echo $query_string; // 输出：name=John&age=30&city=New+York

In the above code, an associative array containing three keys and corresponding values ​​is first defined. Then the array is converted into a query string by calling the http_build_query() function.

As you can see, the generated query string has three parameters, namely "name", "age" and "city". Each parameter corresponds to its key in the array, and the value is the corresponding array value. In the query string, each parameter and the corresponding value are linked by an equal sign ("="), and different parameters are linked by the "&" symbol. Spaces in the value are replaced with plus signs (" ").

The second parameter of the http_build_query() function can be used to specify the delimiter between parameters and the replacement character for spaces in the value. For example, we can change the symbol "&" between parameters to the symbol ";" and change the space in the value to " ":

$data = array(
    'name' => 'John Doe',
    'age' => 35,
    'city' => 'London'
);

$query_string = http_build_query($data, '', ';', PHP_QUERY_RFC3986);

echo $query_string; // 输出：name=John%20Doe;age=35;city=London

In the above code, the second parameter is the null character String, indicating the use of the default symbol "&" between parameters. The third parameter is the symbol ";", which means to use this symbol as the separator between parameters. The fourth parameter is the constant PHP_QUERY_RFC3986, which means using " " to replace spaces in the value.

In actual development, converting PHP arrays into query strings is a very common operation. This task can be easily accomplished using the http_build_query() function, with custom separators and space replacement characters via the second parameter.

The above is the detailed content of How to convert php array to query string. For more information, please follow other related articles on the PHP Chinese website!