Question

I’m not exactly a JS pro, and while not pretty or efficient, this works.

Effectively I have repeating field groups in the form, and allow the user to copy data from the first to all 5 if they want to.

How do I make this code more efficient?

function data_copy() {
if(document.pixelform.copy[0].checked){

document.pixelform.pixelpostclickinterval2.value=document.pixelform.pixelpostclickinterval1.value;
document.pixelform.pixelpostviewinterval2.value=document.pixelform.pixelpostviewinterval1.value;
document.pixelform.pixelsegmentinterval2.value=document.pixelform.pixelsegmentinterval1.value;

document.pixelform.pixelpostclickinterval3.value=document.pixelform.pixelpostclickinterval1.value;
document.pixelform.pixelpostviewinterval3.value=document.pixelform.pixelpostviewinterval1.value;
document.pixelform.pixelsegmentinterval3.value=document.pixelform.pixelsegmentinterval1.value;

document.pixelform.pixelpostclickinterval4.value=document.pixelform.pixelpostclickinterval1.value;
document.pixelform.pixelpostviewinterval4.value=document.pixelform.pixelpostviewinterval1.value;
document.pixelform.pixelsegmentinterval4.value=document.pixelform.pixelsegmentinterval1.value;

document.pixelform.pixelpostclickinterval5.value=document.pixelform.pixelpostclickinterval1.value;
document.pixelform.pixelpostviewinterval5.value=document.pixelform.pixelpostviewinterval1.value;
document.pixelform.pixelsegmentinterval5.value=document.pixelform.pixelsegmentinterval1.value;

} else {

document.pixelform.pixelpostclickinterval2.value="";
document.pixelform.pixelpostviewinterval2.value="";
document.pixelform.pixelsegmentinterval2.value="";

document.pixelform.pixelpostclickinterval3.value="";
document.pixelform.pixelpostviewinterval3.value="";
document.pixelform.pixelsegmentinterval3.value="";

document.pixelform.pixelpostclickinterval4.value="";
document.pixelform.pixelpostviewinterval4.value="";
document.pixelform.pixelsegmentinterval4.value="";

document.pixelform.pixelpostclickinterval5.value="";
document.pixelform.pixelpostviewinterval5.value="";
document.pixelform.pixelsegmentinterval5.value="";

}
}

Answer 1

Use a loop:

for (var i = 2; i <= 5; i++)
{
  document.pixelform["pixelpostclickinterval" + i].value=document.pixelform.pixelpostclickinterval1.value;
  document.pixelform["pixelpostviewinterval" + i].value=document.pixelform.pixelpostviewinterval1.value;
  document.pixelform["pixelsegmentinterval" + i].value=document.pixelform.pixelsegmentinterval1.value;
}