What are common syntax errors?

Common syntax errors include:

1. Missing Semicolons: Not placing a semicolon at the end of a statement (e.g., in C++ or Java).

   std::cout << "Hello World" // Missing semicolon here!
   

2. Mismatched Parentheses or Brackets: Not closing parentheses or brackets properly.

   print("Hello World"  # Missing closing parenthesis
   

3. Incorrect Indentation: In languages like Python, improper indentation can lead to syntax errors.

   def my_function():
   print("Hello")  # This line should be indented
   

4. Using Reserved Keywords Incorrectly: Using keywords inappropriately or as variable names.

   int return = 5;  // 'return' is a reserved keyword
   

5. Incorrect Variable Declarations: Not following the correct syntax for declaring variables.

   var 1name = "John";  // Variable names cannot start with a number
   

6. Unclosed Strings: Forgetting to close a string with the appropriate quotation marks.

   var greeting = "Hello;  // Missing closing quote
   

7. Extra or Missing Commas: Incorrectly placing commas in lists or function arguments.

   var numbers = [1, 2, 3,];  // Extra comma at the end
   

Identifying and fixing these errors is crucial for successful code compilation or execution.