for (i=1; i<=length(T); i++) printf(T[i]);
caused the array T to be filled with many null values. At the beginning, length(T) was 6. When i was incremented to 4, it created new array element T[4],...
In AWK, arrays are associative and array subscripts are always strings. Arrays can be sparse as in your example. If you use an array subscript (expression index) to refer to an array element that...