Substring comparison across columns within Google Apps Script - google-apps-script

Question

I have a large dataset pasted into Google Sheets. I want to compare two columns in this sheet.
The first column is filled with long strings, I only care about the first character in each cell in this column.
The second column is text-based. I want to paste data into a new sheet if the string in column A starts a number (not a letter) and the text in column B is "Early".
My challenge is using Javascript to get only the substring of 1 character for column A. The error is "TypeError: str.substring is not a function." I have also tried slice() as well to no effect. Is this not supported in Apps Script?
How can I isolate those first characters and then compare alongside the other column?
I also then need to push the rows that meet this criteria in both columns to a new tab.
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheetByName('data');
var str = sheet.getRange('A:A').getValues();
var char = str.substring(0,2);
var stage = sheet.getRange('B:B');
var endColumn = sheet.getLastColumn();
var value_stage = (stage.getValues());
var value_char = (char.getValues());
var csh = ss.getSheetByName('new_sheet'); //destination sheet
var data = [];
var j =[];
for (i=0; i<value_char.length;i++) {
if
(
(
( value_char[i] == '0') ||
( value_char[i] == '1') ||
( value_char[i] == '2') ||
( value_char[i] == '3') || etc... )
&&
( value_stage[i] == 'Early')
)
data.push.apply(data,sheet.getRange(i+1,1,1,endColumn).getValues());
j.push(i);
}
}
csh.getRange(csh.getLastRow()+1,1,data.length,data[0].length).setValues(data);
SAMPLE DATA BELOW:
**ID** **Stage** **Name**
A texthere Early Bob
B abcdefgh Late Sally
52 texthere Early Jim
C thesdfas Late Allan
00 tsdfsdfd Late Susan
11 qqwerrww Early Ryan
Q tsdfsagd Early Sarah
98 fdsafads Early Evan
09 fdasfdsa Early Paul
10 abcdefgh New Megan
10 abcdefgh Early Cooper
NOTE: in the real dataset, columns A and B are actually K & L
And the ID column has those spaces between the early part of the string and the end. This is what I am trying to slice off

Answer 1

Try this:
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sh=ss.getSheetByName('data');
var svs=sh.getRange(1,2,sheet.getLastRow(),2).getValues();
var csh=ss.getSheetByName('new_sheet');
var data=[];
var j=[];
svs.forEach(function(r,i){
if((r[0].slice(0,1)=='1' || r[0].slice(0,1)=='2') && r[1]=='Early') {
//do what you want in here
}
});