How JavaScript uses error trapping

github
In JavaScript, error trapping usually uses try...catch...finallythe struct. This allows you to try to execute code that might throw an error, and provides a way to handle the error if something goes wrong.

Here is try...catch...finallythe basic structure of a :

try {
    
    
    // 尝试执行的代码
    // 如果在这里发生错误，将跳转到 catch 块
    throw new Error("This is an error!");  // 这会触发 catch 块
} catch (error) {
    
    
    // 当 try 块中的代码出错时执行的代码
    console.error("An error occurred:", error.message);
} finally {
    
    
    // 这个块中的代码总是执行，无论 try 块中是否发生错误
    console.log("Always executed");
}

In the code above:

• tryBlocks contain code that you expect to execute, but where errors may occur.
• catchBlocks contain the code you want to execute when an error occurs. It can receive a parameter representing the error object that was thrown.
• finallyBlocks contain code that is executed whether or not an error occurs.

Note : finallyblock is optional, you don't have to try...catchuse it in every structure.

Using try...catchcan help you write more robust code, especially when you're not sure that some code will always work correctly (e.g. fetching data from an external API, parsing user input, etc.).