Compilation error c

In other words, syntax errors occur when a programmer does not follow the set of rules defined for the syntax of C language. Syntax errors are sometimes also called compilation errors because they are always detected by the compiler. Generally, these errors can be easily identified and rectified by programmers

A compile-time error generally refers to the errors that correspond to the semantics or syntax. A runtime error refers to the error that we encounter during the code execution during runtime. Fixation. We can easily fix a compile-time error during the development of code. A compiler cannot identify a runtime error.

Error is an illegal operation performed by the user which results in abnormal working of the program. 
Programming errors often remain undetected until the program is compiled or executed. Some of the errors inhibit the program from getting compiled or executed. Thus errors should be removed before compiling and executing. 
The most common errors can be broadly classified as follows.

Type of errors:

1. Syntax errors: Errors that occur when you violate the rules of writing C/C++ syntax are known as syntax errors. This compiler error indicates something that must be fixed before the code can be compiled. All these errors are detected by compiler and thus are known as compile-time errors. 
   Most frequent syntax errors are: 
   • Missing Parenthesis (})
   • Printing the value of variable without declaring it
   • Missing semicolon like this:

// C program to illustrate// C program to illustrate// syntax error#include<stdio.h>void main(){ int x = 10; int y = 15; printf(“%d”, (x, y)) // semicolon missed}

Error: 

error: expected ';' before '}' token

• Syntax of a basic construct is written wrong. For example : while loop

// C program to illustrate// C program to illustrate// syntax error#include<stdio.h>int main(void){ // while() cannot contain “.” as an argument. while(.) { printf(“hello”); } return 0;}

Error:

error: expected expression before '.' token
     while(.) 

• In the given example, the syntax of while loop is incorrect. This causes a syntax error.