a data type whose values are sequence of characters
string
pros of primitive strings (2)
- more convenient
- many operations are built-in
cons of primitive strings
implementation is more complex
pros of array-of-char strings (2)
- simpler implementation
- closer to memory
cons of array-of-char strings (2)
- more manual work
- more error-prone
design issues of array types (7)
- subscript types
- range checking
- binding of subscript type and range
- storage binding
- initialization
- row length
- array slices
is arr[5.26] a valid array subscript?
yes (in javascript), but returns undefined
the type of the subscript is usually bound [statically/dynamically]
statically
the range of valid subscripts is usually bound [statically/dynamically]
dynamically
arrays differ in __ and __
when their size is known,
where they live in memory
on array categories:
range is bound statically and storage allocation is done before run time
static array
on array categories:
range is bound statically but storage allocation is done when the declaration is elaborated
fixed stack-dynamic array
on array categories:
range and storage are bound dynamically once elaborated
stack-dynamic array
on array categories:
range and storage are bound when the program requests them during execution
fixed heap-dynamic array
on array categories:
array can grow and shrink during program execution
heap-dynamic array
rectangular or ragged array?
- each row has the same column size
- each column has the same row size
rectangular array
rectangular or ragged array?
the number of columns for each row need not to be the same
ragged array
row or col major order?
array is stored by rows
row major order
row or col major order?
array is stored by cols
col major order
