Coder Snippets Useful tips and snippets I find or come up with.

4Dec/09Off

Array to JSON function

/**
 * Converts an associative array of arbitrary depth and dimension into JSON representation.
 *
 * NOTE: If you pass in a mixed associative and vector array, it will prefix each numerical
 * key with "key_". For example array("foo", "bar" => "baz") will be translated into
 * {'key_0': 'foo', 'bar': 'baz'} but array("foo", "bar") would be translated into [ 'foo', 'bar' ].
 *
 * @param $array The array to convert.
 * @return mixed The resulting JSON string, or false if the argument was not an array.
 * @author Andy Rusterholz
 */
function array_to_json( $array ){

    if( !is_array( $array ) ){
        return false;
    }

    $associative = count( array_diff( array_keys($array), array_keys( array_keys( $array )) ));
    if( $associative ){

        $construct = array();
        foreach( $array as $key => $value ){

            // We first copy each key/value pair into a staging array,
            // formatting each key and value properly as we go.

            // Format the key:
            if( is_numeric($key) ){
                $key = "key_$key";
            }
            $key = "'".addslashes($key)."'";

            // Format the value:
            if( is_array( $value )){
                $value = array_to_json( $value );
            } else if( !is_numeric( $value ) || is_string( $value ) ){
                $value = "'".addslashes($value)."'";
            }

            // Add to staging array:
            $construct[] = "$key: $value";
        }

        // Then we collapse the staging array into the JSON form:
        $result = "{ " . implode( ", ", $construct ) . " }";

    } else { // If the array is a vector (not associative):

        $construct = array();
        foreach( $array as $value ){

            // Format the value:
            if( is_array( $value )){
                $value = array_to_json( $value );
            } else if( !is_numeric( $value ) || is_string( $value ) ){
                $value = "'".addslashes($value)."'";
            }

            // Add to staging array:
            $construct[] = $value;
        }

        // Then we collapse the staging array into the JSON form:
        $result = "[ " . implode( ", ", $construct ) . " ]";
    }

    return $result;
}