The document explains five types of errors in C programming: syntax errors, runtime errors, logical errors, linker errors, and semantic errors, detailing their definitions and examples. Syntax errors occur during compilation due to incorrect code structure, runtime errors happen during execution, logical errors produce incorrect output despite valid code, linker errors prevent executable creation, and semantic errors arise from unrecognized code meaning. Each error type is illustrated with programming examples to enhance understanding.

1. A L G O R I T H M
• Algorithm to swap two numbers.
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Hint
a=a+b
b=a-b
a=a-b

2. V I S U A L I Z A T I O N T O O L
• https://pythontutor.com/visualize.html
• Game with scratch tool
• ScratchTool - https://scratch.mit.edu/projects/editor/?tutorial=getStarted
• Reference link
• https://www.youtube.com/watch?v=eAJ3AS76ZLo
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3. PROGRAMM
ING IN C

4. TYPES OF ERRORS
• There are 5 types of error in C:
• Syntax Errors
• Runtime Errors
• Logical Errors
• Linked Errors
• Semantic Errors
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5. SYNTAX ERRORS
 Syntax errors are also known as the compilation errors as
they occurred at the compilation time, or we can say that the
syntax errors are thrown by the compilers.
These errors are mainly occurred due to the mistakes while typing
or do not follow the syntax of the specified programming language.
These mistakes are generally made by beginners only because they
are new to the language.
These errors can be easily debugged or corrected. 5

6. C O M P I L E R A N D A S S E M B L E R
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7. SYNTAX ERRORS
• #include <stdio.h>
• int main()
• {
• a = 10;
• printf("The value of a is : %d", a);
• return 0;
• }
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8. RUNTIME ERRORS
Sometimes the errors exist during the execution-time even
after the successful compilation known as run-time errors.
When the program is running, and it is not able to
perform the operation is the main cause of the run-time
error.
The division by zero is the common example of the run-
time error.
These errors are very difficult to find, as the compiler does
not point to these errors. 8

9. RUNTIME ERRORS
#include <stdio.h>
int main()
{
int array[5];
printf("%d", array[10]);
return 0;
}
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Some common examples of runtime
errors are:
• Division by zero
• Null pointer dereferencing
• Array index out of bounds
• Resource leaks (e.g., memory or
open file handles)

10. LOGICAL ERRORS
The logical error is an error that leads to an undesired output.
 These errors produce the incorrect output, but they are error-free,
known as logical errors.
These types of mistakes are mainly done by beginners.
The occurrence of these errors mainly depends upon the logical
thinking of the developer.
If the programmers sound logically good, then there will be fewer
chances of these errors.
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11. L O G I C A L E R R O R - E X A M P L E
• int main()
• {
• int a, b, c;
• a = 2;
• b = 3;
• c = a - b;
• printf("The sum of a and b is %d", c);
• return 0;
• }
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12. LINKER ERRORS
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Linker errors are mainly generated when the executable file of the
program is not created.
This can be happened either due to the wrong function prototyping or usage
of the wrong header file.
For example, the main.c file contains the sub() function whose declaration
and definition is done in some other file such as func.c.
During the compilation, the compiler finds the sub() function in func.c file,
so it generates two object files, i.e., main.o and func.o.
 At the execution time, if the definition of sub() function is not found in
the func.o file, then the linker error will be thrown.
The most common linker error that occurs is that we use Main() instead
of main().

13. L I N K E R E R R O R
• Linker is a program that takes the object files generated by the
compiler and combines them into a single executable file.
• Linker errors are the errors encountered when the executable file of
the code can not be generated even though the code gets compiled
successfully.
• This error is generated when a different object file is unable to link
with the main object file.
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14. L I N K E R E R R O R - E X A M P L E
• #include <stdio.h>
•
• void Main() {
• int var = 10;
• printf("%d", var);
• }
• Output
• undefined reference to `main'
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15. S E M A N T I C E R R O R
Errors that occur because the compiler is unable to understand the
written code are called Semantic Errors.
When a sentence is syntactically correct but has no meaning, semantic
errors occur. This is similar to grammatical errors.
If an expression is entered on the left side of the assignment operator, a
semantic error may occur.
Most commonly occurring sematic errors:
use of un-initialized variables, type compatibility, and array index out of
bounds.
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16. S E M A T I C E R R O R - E X A M P L E
• #include <stdio.h>
• void main() {
• int a, b, c;
•
• a * b = c;
• // This will generate a semantic error
• }
• Output
• error: lvalue required as left operand of assignment
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17. W H A T T Y P E O F E R R O R ?
• #include<stdio.h>
• int main() {
• int a, b, c;
• a = 2
• b = 3;
• c = a + b;
• printf("The sum of a and b is %d", c);
• return 0;
• }
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