11.Differences

 

Differences:

Variables used in a program must be declared before using them

Every C statement must be terminated with a semicolon (;)

A C program must be placed within the structure that is the main( ) function.

 

Need of accepting data from the console input device (Keyboard)

 

 

 

 

 

 

The above program adds only two numbers that is 45 and 50. If we want to add any other numbers then, the program must be modified. Say for example we want to add 125 and 256 then; the program must be modified as.

 

 

 

 

 

 

 

 

We need to modify the program every time need to add two different numbers.

 

Need of scanf( ):

 

It is not a good practice to change the program, whenever input to the program need to change.

Scanf( ) is a function used to accept the data from the user while executing the program.

Different inputs can be given for different executions without changing the program.

The scanf accepts the data from the user and stores into the specified variables

In scanf the representation characters and the addresses of variables must be specified.

Syntax:

	scanf(“<representation characters>”,list of addresses of variables);

 

 

 

 

Example:

 

 

 

 

 

 

 

 

 

 

 

 

Example explained:

During the run-time scanf( ) prompts and accepts the number from user and stores into the variable x

 

 

 

 

Example: