Get vs Getline

1
Get vs Getline

• Using Ada.text_io.get requires that the user
  enter exactly the number of characters specified.
• For example
• Somestring string(1..20)
• Begin
• Ada.text_io.get(itemgtsomestring)
• Requires the user enter 20 characters!

2
Get vs Getline

• An alternative is to use Ada.text_io.get_line
• For example
• Subtype str_lngth_type is integer range 0..20
• Str_lngth str_lngth_type
• Somestring string(1..20)
• Begin
• Ada.text_io.get_line(itemgtsomestring,
  lastgtstr_lngth)
• This will read characters into the string until
  EOL

3
Problem

• If the user only enters 5 characters and then
  presses return, what is in the other 15
  characters?
• Subtype str_lngth_type is integer range 0..20
• Str_lngth str_lngth_type
• Somestring string(1..20)
• Begin
• Ada.text_io.get_line(itemgtsomestring,
  lastgtstr_lngth)
• Ada.text_io.put(itemgtsomestring)
• What does this output?

4
String Slicing

• String slicing fixes this problem
• Subtype str_lngth_type is integer range 0..20
• Str_lngth str_lngth_type
• Somestring string(1..20)
• Begin
• Ada.text_io.get_line(itemgtsomestring,
  lastgtstr_lngth)
• Ada.text_io.put(itemgtsomestring(1..str_lngth))
• Only print the characters that were entered

5
With ada.text_io Procedure sample
IS Max_Name_length constant integer
20 Subtype name_length_type is integer range
0..Max_Name_length First_name_length
name_length_type Last_name_length
name_length_type First_name string(1..max_name_
length) Last_name string(1..max_name_length)
Begin --sample ada.text_io.put(itemgtEnter
first namegt ) ada.text_io.get_line(itemgtfirst_
name, lastgt first_name_length) ada.text_io.put(
itemgt Enter last namegt ) ada.text_io.get_line
(itemgtlast_name, lastgt last_name_length) ada.t
ext_io.put(itemgt first_name(1..first_name_length)
) ada.text_io.put(itemgt ) ada.text_io.put(
itemgt last_name(1..last_name_length) ada.text_i
o.new_line End sample