Why is my file_text_read_string not working in GML?

I have the below GML code where I am attempting to read strings from "mygame.txt". When I run the code, the array is just filled with "". I found the buffer section of code and I can see that the var s actually contains the contents of my game. Any idea why the array, arr[] does not properly read the string?

lines= 0
var file = file_text_open_read("mygame.txt"); // need to store in "data files" folder

if (file!= -1){
    while (!file_text_eof(file)) {
        file_text_readln(file);
        lines++;
    }
    var file_buffer = buffer_load("mygame.txt");
    var s = buffer_read(file_buffer, buffer_string);
    buffer_delete(file_buffer);
    for (var i = 0; i < lines; ++i;){
        arr[i] = file_text_read_string(file);
        file_text_readln(file);
    }
    file_text_close(file);

    for (var i = 0; i < 1; ++i;){

    }}

The array arr[] is displaying blanks because in

while (!file_text_eof(file)) {
        file_text_readln(file);
        lines++;
    }

I was reading the file through to the end of the file in order to mistakenly get the # of lines in the file for the for loop.

 for (var i = 0; i < lines; ++i;){
        arr[i] = file_text_read_string(file);
        file_text_readln(file);
    }

At this point, I am already at the end of the file and therefore no more lines exist. The above for loop processed regardless because the it doesn't care that I was already at the end of file. So all of the indexes in arr[] are blank because it's trying to read lines that don't exist.

To resolve, after the while loop I closed and reopened the file before the for loop.

lines= 0 var file = file_text_open_read("mygame.txt"); // need to store in "data files" folder

if (file!= -1){
    while (!file_text_eof(file)) {
        file_text_readln(file);
        lines++;
    }
    file_text_close(file);
    file_text_open_read(file);
    for (var i = 0; i < lines; ++i;){
        arr[i] = file_text_read_string(file);
        file_text_readln(file);
    }
    file_text_close(file);

    for (var i = 0; i < 1; ++i;){

    }}

Another code example by YellowAfterlife is the proper coding

    lines = 0;
    var file = file_text_open_read("mygame.txt");
    if (file != -1) {
        while (!file_text_eof(file)) {
            arr[lines] = file_text_read_string(file);
            file_text_readln(file);
            lines++;
            }
        file_text_close(file);
        // arr is now populated with lines from the file
    }