phpの配列をjson形式に変換する方法の紹介

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;
}