CSCI 235 — diff C Java 1

Our reference

• Chapters 1 to 6 and 13 of An Introduction to the C Programming Language and Software Design

But let’s start with some Fall 2015 CSCI 255 notes on C vs Java or the Fall 2011 ECE 209 C overview.

Chapter 1 — Introduction

• Designed to compete with assembly language
• Has a goto
• No objects
• if, while and for
  • but the condition is an int not a boolean
• C preprocessor

Chapter 2 — Types, Operators, and Expressions

This discussion applies to the C99 standard. Before C99, it was chaos.

• Integers and characters
  • C has similar integer types to Java but is quite a bit more flexible about the range of allowed values. See Wikipedia for more information.
  • There are signed and unsigned integer values. This can be useful. Java short, int, and double types are unsigned.
  • C has no boolean type. A non-zero integer is considered to be true and 0 is considered to be false. C99 does have a “type” _Bool that is similar to the Java boolean.
  • There is no byte in C.
  • Java char is like a C unsigned short.
• Standard C I/O is important and influenced Java I/O (more O than I)
• C and Java have similar cast operations, but narrowing without cast is allowed in C.

Chapter 3 — Branching and Iteration

• Looks like Java with a goto.

Chapter 4 — Functions

• functions are not methods.
• C has function prototypes to specify the function interface.
  • See fprintf man page.
• The main function returns an integer to indicate success or failure
  • Oddly, success is usually 0 — see mkdir.
  • exit is a bailout.
• C standard library has many useful functions.

Chapter 5 — Scope and Extent

This is not Java.

• Spring 2017 CSCI 255 notes

Chapter 13 — Input and Output

• %[flags][width][.precision][length]specifier
  • The C/C++ printf is a bit like the Java format
• %[*][width][length]specifier
  • The C/C++ scanf is very different from the Java Scanner
  • C input uses pointers
• Blame it all on FORTRAN
• In practice C++ I/O, with its heavy use of operator overloading and multiple inheritance, resembles neither C nor Java I/O
• File control: fopen and fclose
• Stream access
  • Character: fgetc and fputc
  • String: fgets and fputs
  • Record: fread and fclose
• Random access: fseek and ftell
• Command line arguments
• Let‘s look at some Fall 2010 ECE 209 formatting notes

C I/O example from Fall 2017

Pay attention! This is a department required assignment.

• File programmng assignment
• Solved file programming assignment
  • The C code
  • The Makefile