Button that copies text entry values from column 1 of matrix table to other columns

A few things:

1. this

   inside the click handler refers to the click event, not the question object. Add

   var qobj = this;

   before the click handler then

   qobj

   instead of

   this

   inside the click handler.


2. It would be better to use nested loops to set the values


3. Use

   console.log

   instead of

   alert

   for debugging

Thank you so much TomG !
Adding the qobj reference solved my problem. I tried for a while to implement some kind of looping to set the values, but couldn't figure it out. I'm not sure how to get the values of a specific column, and then loop over the remaining columns. But even if it's not elegant, here is the code that works for me (with an added button to do the same thing across the weekend columns):
Qualtrics.SurveyEngine.addOnReady(function()
{
var qobj = this;
jQuery("#copy_weekdays").click(function() {
var l1mon = qobj.getChoiceValue(1,1); 
var l2mon = qobj.getChoiceValue(2,1);
var l3mon = qobj.getChoiceValue(3,1);
var l4mon = qobj.getChoiceValue(4,1);
qobj.setChoiceValue(1,2,l1mon);
qobj.setChoiceValue(2,2,l2mon);
qobj.setChoiceValue(3,2,l3mon);
qobj.setChoiceValue(4,2,l4mon);
        qobj.setChoiceValue(1,3,l1mon);
qobj.setChoiceValue(2,3,l2mon);
qobj.setChoiceValue(3,3,l3mon);
qobj.setChoiceValue(4,3,l4mon);
        qobj.setChoiceValue(1,4,l1mon);
qobj.setChoiceValue(2,4,l2mon);
qobj.setChoiceValue(3,4,l3mon);
qobj.setChoiceValue(4,4,l4mon);
        qobj.setChoiceValue(1,5,l1mon);
qobj.setChoiceValue(2,5,l2mon);
qobj.setChoiceValue(3,5,l3mon);
qobj.setChoiceValue(4,5,l4mon);
    });

jQuery("#copy_weekends").click(function() {
var l1sat = qobj.getChoiceValue(1,6); 
var l2sat = qobj.getChoiceValue(2,6);
var l3sat = qobj.getChoiceValue(3,6);
var l4sat = qobj.getChoiceValue(4,6);
qobj.setChoiceValue(1,7,l1sat);
qobj.setChoiceValue(2,7,l2sat);
qobj.setChoiceValue(3,7,l3sat);
qobj.setChoiceValue(4,7,l4sat);
    });
});
And here's what it looks like:

https://community.qualtrics.com/XMcommunity/discussion/comment/50692#Comment_50692Nested loops would look something like:
jQuery("#copy_weekdays").click(function() {
var mon;
for(i=1,i<=4;i++) {
mon = qobj.getChoiceValue(i,1);
for(j=2,j<=5;j++) { qobj.setChoiceValue(i,j,mon); }
}
});

Thanks again TomG! I have now updated my code to the following and it works perfectly:
Qualtrics.SurveyEngine.addOnReady(function()
{
var qobj = this;

jQuery("#copy_weekdays").click(function() {
  var mon;
  for(i=1;i<=4;i++) {
    mon = qobj.getChoiceValue(i,1);
    for(j=2;j<=5;j++) { qobj.setChoiceValue(i,j,mon); }
  }
});

jQuery("#copy_weekends").click(function() {
  var sat;
  for(i=1;i<=4;i++) {
    sat = qobj.getChoiceValue(i,6);
    for(j=7;j<=7;j++) { qobj.setChoiceValue(i,j,sat); }
  }
});

});

TomG comes up with another custom code solution! Thank you so much for your valuable contributions to the community! 👏