how to use the variable in a for loop in Javascript?

Question

I have a dataTable which I need to iterate through. so I have this code:

var tableSize = $('#j_idt11\\:dataTable tbody tr').length;
for(i = 0;i< tableSize;i++){
    var test1 = document.getElementById("j_idt11:dataTable:0:updFoodType").textContent;
    if(test1 == "food")
        alert("hey");
}

but I really want to use the i in the for loop. I thought something like this:

var tableSize = $('#j_idt11\\:dataTable tbody tr').length;
for(i = 0;i< tableSize;i++){
    var test1 = document.getElementById("j_idt11:dataTable:[i]:updFoodType").textContent;
     if(test1 == "food")
         alert("hey");
}

but that doesn't work. how must I use the syntax? Thanks!

It's easier for us to help you if your code is properly formatted. — Felix Kling
– Felix Kling, Commented Jul 25, 2012 at 18:31
possible duplicate of How do i put a variable in a string using javascript — Felix Kling
– Felix Kling, Commented Jul 25, 2012 at 18:33
If you could write a better selector you could just use $(..).each(fn) .. and if using jQuery (or another magical $ variant), it is sort of silly to mix in usages of document.getElementById as well. — user166390
– user166390, Commented Jul 25, 2012 at 18:37

Andrew · Accepted Answer · 2012-07-25 18:30:50Z

1

The for loop has nothing to do with it, you need to concatenate the string,

for(var i = 0;i< tableSize;i++){
  var test1 = document.getElementById("j_idt11:dataTable:" + i + ":updFoodType").textContent;
  if(test1 == "food")
     alert("hey");
}

Also be careful with globals, you should declare i in the local scope as well.

answered Jul 25, 2012 at 18:30

Andrew

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Comments

Hunter McMillen · Accepted Answer · 2012-07-25 18:31:07Z

1

You just need to concatenate the value of i with your string:

var tableSize = $('#j_idt11\\:dataTable tbody tr').length;
for(i = 0;i< tableSize;i++)
{
   var test1 = document.getElementById("j_idt11:dataTable:" + i + ":updFoodType").textContent;
   if(test1 == "food")
      alert("hey");
}

answered Jul 25, 2012 at 18:31

Hunter McMillen

61.8k25 gold badges124 silver badges176 bronze badges

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