Solve the 'error: expected primary-expression before ')' token' problem in C++ code

Solve the "error: expected primary-expression before ')' token" problem in C code

In C programming, we sometimes encounter some errors Tips, such as "expected primary-expression before ')' token". This error is usually caused by incorrect syntax or expressions used in the code, causing the compiler to fail to understand the meaning of the code. This article will introduce some common situations where this error occurs and provide corresponding solutions.

Situation 1: Function call error
In C, we usually use parentheses to call functions, but sometimes we forget to add parentheses after the function name. For example:

cout << "Hello, World!" << endl;

This line of code should be written as:

cout << "Hello, World!" << endl;

The solution is to add parentheses after the function name.

Scenario 2: Missing header files or namespaces
In C, we need to use header files or namespaces to introduce some standard library functions or classes. If we forget to include the corresponding header file or namespace, the compiler will report an error. For example:

vector<int> numbers;

This line of code should be written as:

#include 
using namespace std;

vector<int> numbers;

The solution is to introduce the corresponding header file or namespace according to the code needs.

Case 3: Syntax error
Syntax error is one of the most common errors in C programs. In some cases, we may make some mistakes in syntax that cause the compiler to not parse the code correctly. For example:

int sum = add(a b);

This line of code should be written as:

int sum = add(a, b);

The solution is to check the code for syntax errors and correct it if necessary.

Case 4: Missing semicolon
In C, each line of code should end with a semicolon. If we forget to add a semicolon at the end of the code, the compiler will complain. For example:

int a = 10
int b = 20;

This code should be written as:

int a = 10;
int b = 20;

The solution is to add a semicolon at the end of the code.

Case 5: Missing operator
C is a strongly typed language, which requires us to use the correct operator when performing operations. If we forget to add operators to our code, the compiler will throw an error. For example:

int sum = a + b

This line of code should be written as:

int sum = a + b;

The solution is to add the correct operator to the code.

Through the above examples of common situations, we can see that the way to solve this error is usually to check the syntax errors in the code and make appropriate modifications. Of course, there are other situations that may cause this error, which need to be analyzed and solved based on the specific code.

Summary:
In C programming, when encountering the error "error: expected primary-expression before ')' token", you need to pay attention to the following aspects:

1. Check whether the function call is correct and whether the parentheses are forgotten.
2. Check whether there are missing header files or namespace introductions.
3. Check if there are any grammatical errors, such as missing commas, semicolons, etc.
4. Check for missing operators.

Through the above methods, we can better solve such errors and further learn and improve our abilities in C programming.

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