C Programming Error Types – Runtime, Compile & Logical Errors

While writing c programs, errors also known as bugs in the world of programming may occur unwillingly which may prevent the program to compile and run correctly as per the expectation of the programmer.

Basically there are three types of errors in c programming:

1. Runtime Errors
2. Compile Errors
3. Logical Errors

C Runtime Errors

C runtime errors are those errors that occur during the execution of a c program and generally occur due to some illegal operation performed in the program.

Examples of some illegal operations that may produce runtime errors are:

• Dividing a number by zero
• Trying to open a file which is not created
• Lack of free memory space

It should be noted that occurrence of these errors may stop program execution, thus to encounter this, a program should be written such that it is able to handle such unexpected errors and rather than terminating unexpectedly, it should be able to continue operating. This ability of the program is known as robustness and the code used to make a program robust is known as guard code as it guards program from terminating abruptly due to occurrence of execution errors.

Compile Errors

Compile errors are those errors that occur at the time of compilation of the program. C compile errors may be further classified as:

Syntax Errors

When the rules of the c programming language are not followed, the compiler will show syntax errors.

For example, consider the statement,

int a,b:

The above statement will produce syntax error as the statement is terminated with : rather than ;

Semantic Errors

Semantic errors are reported by the compiler when the statements written in the c program are not meaningful to the compiler.

For example, consider the statement,

b+c=a;

In the above statement we are trying to assign value of a in the value obtained by summation of b and c which has no meaning in c. The correct statement will be

a=b+c;

Logical Errors

Logical errors are the errors in the output of the program. The presence of logical errors leads to undesired or incorrect output and are caused due to error in the logic applied in the program to produce the desired output.

Also, logical errors could not be detected by the compiler, and thus, programmers has to check the entire coding of a c program line by line.