为什么我的功能在使用goto时给我一个"''''''''''''''''''''''''''''''

Question

我的功能是在使用goto时给我"在'}'令牌之前预期的主要表达",我不知道为什么.

在我将它放入函数之前,这段代码按原样运行.

当我用'break'替换'goto'时它会起作用,但我需要知道为什么会这样.

void fileInputLoop(ifstream& inputFile){
    do{

        cout << "Enter data file name: ";
        getline(cin, fileName);
        previousFileName = fileName;
        // The user will press enter to exit data input 
        if(fileName == ""){
            // If no file name is entered, exit this input loop
            goto skip_data_input_loop;

        }else{
            // Check to see if input is an existing file
            inputFile.open(fileName);
            if(!inputFile.is_open()){
                cout << "File is not available." << endl;
            }else{
                // FILE IS OPEN, DO SOMETHING WITH IT
                ReadData(inputFile);
                inputFile.close();
            }
        }
        // If a second++ file is read in, the previous file will be set accordingly
        // This is to track if a duplicate is from the same file or a new file
        previousFileName = fileName;

    }while(true);
    skip_data_input_loop:
}

Answer 1

问题是标签要标记一个语句.换句话说,如果没有声明,您就不能拥有标签.

有了我的评论的警告,你可以通过在标签后面有一个空的"null"语句来解决它:

skip_data_input_loop: /* Empty statement using the semicolon */ ;