How to solve C++ syntax error: 'unexpected token'?

How to solve C syntax error: 'unexpected token'?

In C programming, syntax errors are very common. One of the common errors is 'unexpected token', i.e. unexpected token. This error is usually caused by characters or tokens in the code that do not comply with the grammatical rules. This article will introduce some common 'C unexpected token' errors and provide solutions.

Here are some common 'C unexpected token' errors:

1. Missing semicolon error:
   In C, the semicolon is used to indicate the end of a statement. If you forget to add a semicolon in your code, you will get an 'unexpected token' error.

For example:

int x = 10   // 缺少分号

The correct writing should be:

int x = 10;  // 添加分号

2. Bracket mismatch error:
   The brackets in C must appear in pairs , including parentheses, square brackets, and curly braces. If the brackets are not paired correctly, a syntax error will result.

For example:

if (x > 5 {
    // do something
}

The correct way to write it should be:

if (x > 5) {
    // do something
}

3. Keyword errors:
   In C, some keywords are Used for certain syntax constructs, these keywords can also result in 'unexpected token' errors if used incorrectly.

For example:

int class = 10;  // 错误的使用了关键字'class'

The correct writing should be:

int myClass = 10;  // 使用非关键字进行命名

4. Comment mark error:
   Comments are marks used to explain the code, But if the markup of comments is incomplete or improperly placed, it will also affect the syntax of the code.

For example:

/*
    这是一个错误的注释
    缺少了结束标记

The correct writing should be:

/*
    这是一个正确的注释
*/

5. Quotation mark mismatch error:
   In C, string constants must Surround it with quotation marks. Mismatching or missing quotation marks will also cause a syntax error.

For example:

string name = "John';  // 错误的引号使用

The correct way to write it should be:

string name = "John";  // 引号匹配,正确的写法

Now, let’s look at some ways to solve these errors:

1. Check the code carefully to make sure you haven't missed any semicolons, brackets, quotes, and comment marks. Using your code editor's autocompletion feature can help avoid these errors.
2. Develop good coding habits and pay attention to code formatting and indentation, which will help find potential syntax errors.
3. Make good use of the compiler. Most C integrated development environments (IDEs) will give specific error information and locations when compiling code, which helps to quickly locate and solve syntax errors.
4. Refer to the C syntax rule manual or online resources to learn the syntax rules of C and the correct use of various tags.

To sum up, the key to solving the 'C unexpected token' error is to check the code carefully and follow the correct syntax rules. By cultivating good coding habits, using code editor support, referencing documentation, and learning the syntax rules of C, we can better avoid and solve these errors and improve the quality and efficiency of our code.

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