c# - Select and updating data from datatable -

i select data datatable, using following code,but throws exception not familiar with.

"index outside bounds of array."

tblrooms.select(idroom = 4) value of idroom in thetblroom don't know why causes error.

foreach (datarow dr in tblroomcart.rows) {       datarow drroom = tblrooms.select("idroom =" + dr["idroom"])[0];//here error in line  }

as exception says,index out of bounds,you reading first element (with index 0) there no elements in collection.
same this:

int[] array = new int[0]; int x = array[0];//you exception here

add if statement make sure there @ least 1 element,like:

int[] array = new int[0]; if (array.length > 0) {         int x = array[0]; }

Macro