C vs. Ch

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Introduction

In CS16, we are using the Ch interpreter rather than standard C.

We are using Ch because we believe it will make learning C easier.

But, because your textbook presents standard C, there are a few things that may be helpful for you to know about the differences between Ch and standard C.

Differences

Declaring Variables

• In standard C, all variables must be declared at the beginning of a block of code.
• In Ch, you can declare variables anywhere in a block of code.
• C++ and Java (languages you'll learn in CS24 and CS56) behave the same way as Ch in this regard.

#includes

• In standard C, you must use #include <stdio.h> at the top of a program that uses printf and scanf for input and output
• In standard C, you must use #include <math.h> at the top of a program that uses the sqrt function
• In Ch, you can leave off these #includes, and the program will still work correctly.

program structure

• In standard C, you must format your program as a "main function", typically starting with, for example, int main(void) and ending with return 0;
• In Ch, this is not necessary. Your program can simply be a list of statements.