phone call function

!!!!Write fully functional "working" programs, not just "example" programs!!!!

Requirements Analysis

• Add phone information
• Save phone information
• After the program runs, all phone information will be displayed automatically
• Users can export phone information for backup

Identify variables in requirements

• Save file: txt
• Save as: One call per line
• Interaction: command line

  -ld path path represents the file to be importedThe full name of the phonebook file-sa path.path represents the full name of the phonebook file to be exported-se, save the information to the default file, in the execution file directory-se, save the information to the default file, in the execution file directory

  Because interaction needs to be performed continuously, loop statement needs to be used; it is necessary to judge the characters entered by the userIt is Which one, so you need to use a judgment statement;

Identify features in requirements

• How do I get keyboard input?
• How to read and write text files?