We Keep Coding

Trying to write a basic script for a Google Sheets that will count total missed minutes by late students

I am (VERY) new to Apps Script and JS generally. I am trying to write a script that will automatically tally the difference between student entry time and start time of a course to deliver total minutes missed.
I have been able to get a function working that can do this for a single cell value, but am having trouble iterating it across a range. Doubtless this is due to a fundamental misunderstanding I have about the for loop I am using, but I am not sure where to look for more detailed information.
Any and all advice is appreciated. Please keep in mind my extreme "beginner status".
I have tried declaring a blank variable and adding multiple results of previously written single-cell functions to that total, but it is returning 0 regardless of given information.
I am including all three of the functions below, the idea is that each will do one part of the overall task.
function LATENESS (entry,start) {
return (entry-start)/60000
}
function MISSEDMINUTES(studenttime,starttime) {
const time = studenttime;
const begin = starttime;
if (time=="Present") {
return 0
} else if (time=="Absent") {
return 90
} else {
return LATENESS(time,begin)
}
}
function TOTALMISSED(range,begintime) {
var total = 0
for (let i = 0; i < range.length; i++) {
total = total + MISSEDMINUTES(i,begintime)
}
}```

If you slightly tweak your layout to have the 'missing minutes' column immediately adjacent to the column of names, you can have a single formula which will calculate the missing minutes for any number of students over any number of days:
Name
*
2/6
2/7
2/8
2/9
John Smith
-
Present
Present
Absent
10:06
Lucy Jenkins
-
Absent
Absent
Absent
Absent
Darren Polter
-
Present
Present
Present
10:01
With 'Name' present in A1, add the following to cell B1 (where I've marked an asterisk):
={"mins missed";
byrow(map(
C2:index(C2:ZZZ,counta(A2:A),counta(C1:1)),
lambda(x,switch(x,"Present",0,"Absent",90,,0,1440*(x-timevalue("10:00"))))),
lambda(row,sum(row)))}
We are MAPping a minute value onto each entry in the table (where 'Present'=0, 'Absent'=90 & a time entry = the number of minutes difference between then and 10am), then summing BYROW.

Updated
Based on the example, you could probably have a formula like the below one to conduct your summation:
=Sum(ARRAYFORMULA(if(B2:E2="Absent",90,if(isnumber(B2:E2),(B2:E2-$K$1)*60*24,0))))
Note that k1 has the start time of 10:00. Same sample sheet has working example.
Original Answer
I'm pretty sure you could do what you want with regular sheets formulas. Here'a sample sheet that shows how to get the difference in two times in minutes and seconds... Along with accounting for absent.
Here's the formula used that will update with new entries.
=Filter({if(B2:B="Absent",90*60,Round((C2:C-B2:B)*3600*24,0)),if(B2:B="Absent",90,Round((C2:C-B2:B)*3600*24/60,1))},(B2:B<>""))
This example might not solve all your issues, but from what I'm seeing, there's no need to be using an app script. If this doesn't cover it, post some sample data using Mark down table.

Pasting Values Only For Certain Formulas

I have a large workbook that pulls in weekly data (columns) for hundreds of metrics on several tabs. It pulls this data in via SUMIFS formulas, and on most tabs there are several rows that contain ratios/rates calculated from these SUMIFS formulas.
Here is a toy example.
For each sheet, I would like to paste values only for formulas that are based on 'SUMIFS', and leave the other calculations. I was able to select a range and loop cell-by-cell to accomplish this, but it takes a long time due to the size of the workbook. Is there a way to do this at once in a batch-fashion? Basically, I want to copy and paste-values only if a certain condition exists.

Solution:
Updated - Slight improvement to make it faster by Iamblichus.
I am not quite sure what you have tried so far, but this one works relatively fast for a couple of sheets:
function myFunction() {
let ss = SpreadsheetApp.getActiveSpreadsheet();
let sheets = ['Sheet1','Sheet2'].map(sh=>ss.getSheetByName(sh));
sheets.forEach(sh=>{
let range = sh.getDataRange();
let formula = range.getFormulasR1C1();
let values = range.getValues();
formula.forEach( (fr,fx) =>
{fr.forEach((fc,fy)=>{
let outR=sh.getRange(fx+1,fy+1);
if (fc.toUpperCase().includes('SUMIFS')) outR.setValue(values[fx][fy]);
})})});
}
Please adjust ['Sheet1','Sheet2','Sheet3'] to your needs.
Explanation:
I am iterating through each sheet and I am checking whether the cells contain SUMIFS formula or not. If they do, I overwrite them with their value, otherwise I keep their formula.

How to setup a range in "Script lab" for Office Excel add-ins , using variables (and not hard coded values for cell references)

Script lab shows examples of how to get a range using rows, columns and cell values here:
https://learn.microsoft.com/en-us/office/dev/add-ins/excel/excel-add-ins-ranges-advanced
However, all the values in examples were hardcoded. I could not find on any page any example of how to use variables in the get range? Maybe its a simple javascript thing but I am totally new to it. Can anyone share an example of how to do say?
sheet.getRange("4:9") using variables for number 4 and number 9?
And if you do know that answer for above, can you also share, how to do this using cell references in the below example?
Assume that I can find the values of rows and column names and set them in some variables. How would I use it in below code replacing the values for G1, A1 and E1?
sheet.getRange("G1").copyFrom("A1:E1");
Thanking you in advance for your help!
P.S: I already tried searching on stack overflow with keywords for "script lab range variables" but found no answers. Hence asking here.
Excel.run(function (context) {
var sheet = context.workbook.worksheets.getItem("Sample");
// Group the larger, main level. Note that the outline controls
// will be on row 10, meaning 4-9 will collapse and expand.
sheet.getRange("4:9").group(Excel.GroupOption.byRows);
// Group the smaller, sublevels. Note that the outline controls
// will be on rows 6 and 9, meaning 4-5 and 7-8 will collapse and expand.
sheet.getRange("4:5").group(Excel.GroupOption.byRows);
sheet.getRange("7:8").group(Excel.GroupOption.byRows);
// Group the larger, main level. Note that the outline controls
// will be on column R, meaning C-Q will collapse and expand.
sheet.getRange("C:Q").group(Excel.GroupOption.byColumns);
// Group the smaller, sublevels. Note that the outline controls
// will be on columns G, L, and R, meaning C-F, H-K, and M-P will collapse and expand.
sheet.getRange("C:F").group(Excel.GroupOption.byColumns);
sheet.getRange("H:K").group(Excel.GroupOption.byColumns);
sheet.getRange("M:P").group(Excel.GroupOption.byColumns);
return context.sync();
}).catch(errorHandlerFunction);

So, I got an answer on this here: https://github.com/OfficeDev/office-js-docs-pr/issues/1699
Thanks to AlexJerabek (you can find his id on the above github link).
In summary:
The getRange method takes in a string representing a cell range in the worksheet, such as "A1:D4", "A:D" for just the columns, or "1:4" for just the rows. As long as your variables map to Excel rows or columns, you can use string concatenation to build the argument. You may need to use range.columnIndex, range.rowIndex, and range.getCell to translate to and from zero-based numbers into the letter-based columns.
Based on this answer, I tried below (and it worked):
const sheet = context.workbook.worksheets.getActiveWorksheet();
var firstrow = 1
var lastRow = 6
var range = sheet.getRange(firstrow + ":" + lastRow)

Calculate ArrayFormula per row in Google Sheets

I am trying to perform a calculation on each row using the Array Formula function. When I try to use a range A2:A it tries to perform a calculation on the entire range as opposed to per row.
Which part am I missing to calculate per row?
={"id";ArrayFormula(TEXTJOIN("", TRUE,(LEFT(B2,2)),(A2*86400000)))}
Here is the formula active in a Google Sheet
https://docs.google.com/spreadsheets/d/1YXA_yC_beoe7UXgXZvbj9knNU8ms1MPMgLKrro4G-T0/edit?usp=sharing

Some formulas like Textjoin won't work in an arrayformula. If the formula already takes a range, then it doesn't understand that you want it to calculate row by row. Try this formula. I got rid of the textjoin part, and just used an ampersand to join columns A and B.
={"id";ArrayFormula(iferror(if(A2:A="",,LEFT(B2:B,2)&(A2:A*86400000))))}
`

How to copy multiple ranges from 13 different sheets to a another workbook in Google Docs

I have a Google Spreadsheet with 13 sheets. Each sheet has the same formatting and layout but the data varies. The ranges I need from each sheet are F7:G13 and cell F2. Each row within the F7:G13 range should be paired with Cell F2 and placed into 3 adjacent columns in another workbook (we'll call it Workbook2). So if there is a data point in column F there will be a data point in the adjacent G cell. As long as there is data in the G:F range then the contents of cell F2 needs to be copied over too.
Some potential problems...
The number of rows in the F:G range will vary from 0 to 7 on any given sheet.
Workbook2 has some auto-populated cells (range F1:J14) which will do some calculations based on information copied over. I mention this because unless there is a way to use appendRow on a specific cell range (A:C) it will copy the data starting in row 15 which I do not want.
I think i've included everything but I will gladly clarify anything. Thanks in advance for any help.