Regular Expressions on array

Question

I am trying to edit the first entry in a array before it placed in another file.

This is it:

(["\"NAMES\":\"cs.js\"},[

I want to turn it into this:

([{"NAMES":"cs.js"},[

I'm using an online regex generator, but so far I've only managed to edit to this point with /.["[\]/ and substituting with ([{:

([{"NAMES\":\"cs.js\"},[

Any help given will be appreciated.

EDIT:

Here is some of the code:

var initialCourseArray = new Array() 
initialCourseArray.push(["\"NAMES\":\"cs.js\"},[
{"COURSE_ID":"ENGL 1013"},
{"COURSE_ID":"FAH1"},
{"COURSE_ID":"USHG1"},
{"COURSE_ID":"TECH 1001"},
{"COURSE_ID":"COMS 1403"},
{"COURSE_ID":"COMS 1411"},
{"COURSE_ID":"ENGL 1023"},
{"COURSE_ID":"SS1"},
{"COURSE_ID":"MATH 2914"},

The stuff after is the rest of the values in the array and they do not look like this one so I'm not worried about them.

Second EDIT:

Since there is some confusion about the code that I honestly should have placed in here first, I am using a php file to retreive course data from a test database and then encoding it into JSON, formatting it, and then using fopen and fprintf to place it inside a javascript file. The part I'm giving you is what ends up inside the javascript file.

Third EDIT:

here is the code I am using to format the array. It is very messy because my leader keeps changing the format he wants the result to be in:

$row1 = "\"NAMES\"";
$colon = ":";
$row2 = "\"".$major.".js\"";
$major_name = $row1.$colon.$row2;

//The course data is already loaded into the table. This why I am using array_unshift to place the major_name inside.
array_unshift($major_array, $major_name);

array_push($major_array, "false");
$json_string = json_encode($major_array);

$re = "/.,/";
$subst = "},\r\n";
$json_string = preg_replace($re, $subst, $json_string);

$re2 = "/\,(?=[^.]*$)/";
$subst2 = ",[";
$json_string = preg_replace($re2, $subst2, $json_string, 1);

$first_string = "var initialCourseArray = new Array()";
$second_string = "initialCourseArray.push(";
$end_bracket = "]";
$end_parentheses =")";

Answer 1

There are several issues:

1. Don't manipulate JSON strings

You should never manipulate a string that is the result of json_encode, because you will very likely make the JSON text invalid, which is actually happening in your case.

So using this kind of statements:

$json_string = preg_replace($re, $subst, $json_string);

is asking for trouble. Once you have a $json_string, it should be final. Anything you want to happen to the structure must happen before you call json_encode.

Even if you just want to add line breaks inside a JSON string, don't do it that way. json_code provides a "pretty print" option which will do it for you:

json_encode(...., JSON_PRETTY_PRINT);

2. JavaScript does not have associative arrays

A second problem is that in JavaScript you cannot have something like

["NAMES":"cs.js" ...]

So json_encode will never generate anything like that. If you want named keys in JavaScript (like "NAMES"), you cannot define it as an array, but should define it as an object:

{"NAMES":"cs.js" ...} 

json_encode will do that for you if you provide it the corresponding PHP structure (i.e. an associative array) and let it do its job without tampering.

3. Don't add "false"

It does not seem useful to add "false" as an element to the courses array. In JavaScript you can easily check how many elements there are in an array, so there is no need to put a kind of stop-sign at the end.

Anyway, if in JavaScript you refer to an element in an array that does not exist, you get undefined, which you can verify, much like verifying for the value "false".

I would strongly suggest to leave that out.

Suggested code

The PHP code you provided in your question could be replaced with this:

// Add the names element as a separate item next to the courses array,
// which we put in the "courses" property.
$major_array = array(
    "names" => $major,
    "courses" => $major_array
);

// Turn into JSON text with added line breaks and indentation:
$json_string = json_encode($major_array, JSON_PRETTY_PRINT);

// Don't touch the JSON text anymore, but output it:
echo "var initialCourse = $json_string;";

The output (JavaScript) would be something like:

var initialCourse = {
    "names": "cs",
    "courses": [
        {
            "COURSE_ID": "ENGL 1013"
        },
        {
            "COURSE_ID": "FAH1"
        },
        {
            "COURSE_ID": "USHG1"
        },
        {
            "COURSE_ID": "TECH 1001"
        },
        {
            "COURSE_ID": "COMS 1403"
        },
        {
            "COURSE_ID": "COMS 1411"
        },
        {
            "COURSE_ID": "ENGL 1023"
        },
        {
            "COURSE_ID": "SS1"
        },
        {
            "COURSE_ID": "MATH 2914"
        }
    ]
};

As I mentioned above, this is an object structure, not an array structure, because JavaScript does not allow named keys in an array notation. If in JavaScript you need to iterate over the courses in the above structure, you would address the courses property (which is an array), like this:

for (var course of initialCourse.courses) {
    console.log('course id: ' + course.COURSE_ID);
}

More concise structure

I must say it is a bit of an over-kill to have objects with just one property. This structure would be more concise and efficient:

var initialCourse = {
    "names": "cs",
    "courses": [
        "ENGL 1013",
        "FAH1",
        "USHG1",
        "TECH 1001",
        "COMS 1403",
        "COMS 1411",
        "ENGL 1023",
        "SS1",
        "MATH 2914"
    ]
};

In JavaScript you would iterate over these courses like this:

for (var course of initialCourse.courses) {
    console.log('course id: ' + course);
}

If this interests you, you should just add this line to your PHP code, before any of the PHP code I suggested above:

$major_array = array_map(function ($course) { return $course["COURSE_ID"]; }, $major_array);

Answer 2

If you just want to apply it to that line,

find /"?\\"/ and replace " will do it.