小编Bog*_* M.的帖子

我试图得到一个字符串处理程序,它从用户输入字符串类型变量...但它崩溃了,我想知道为什么？或者我做错了什么......

 string UIconsole::getString(){
    string input;
    getline(cin,input);
    if(input.empty() == false){
        return input;
    }
    else{getString();}
    return 0;
}

编辑:错误:

This application has requested the Runtime to terminate it in an unusual way.
Please contact the application's support team for more information.
terminate called after throwing an instance of 'std::logic_error'
  what():  basic_string::_S_construct null not valid

我需要初始化一个像Map x<Apartment,Vector<Expense>>它允许我,如果我@override的Map方法

Description Resource    Path    Location    Type
The type new Map<Apartment,Vector<Expense>>(){} must implement the inherited abstract method Map<Apartment,Vector<Expense>>.isEmpty()   Repository.java /proj_individual/src/repo   line 12 Java Problem
The type new Map<Apartment,Vector<Expense>>(){} must implement the inherited abstract method Map<Apartment,Vector<Expense>>.size()  Repository.java /proj_individual/src/repo   line 12 Java Problem
The type new Map<Apartment,Vector<Expense>>(){} must implement the inherited abstract method Map<Apartment,Vector<Expense>>.keySet()    Repository.java /proj_individual/src/repo   line 12 Java Problem
The type new Map<Apartment,Vector<Expense>>(){} must implement the inherited abstract method Map<Apartment,Vector<Expense>>.remove(Object)  Repository.java /proj_individual/src/repo   line 12 Java Problem
The …

当我转换JTextField为int 时,我的GUI程序崩溃了.可以帮助我查看这段代码,看看有什么问题,因为我使用了相同的方法,并且它有效.

我所做的:

new JTextLabel l;

在那里得到什么

String A = l.getText() >int i = Interger.parse(A);

码:

btnAdd.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        int nr = Integer.parseInt(txtApt.getText());
        int nrP = Integer.parseInt(txtNrPips.getText());
        String owner = txtOwner.toString();
        Apartment a = new Apartment(nr, nrP, owner, false);
        Expense b = new Expense(Float.parseFloat(textWW.getText()), Float.parseFloat(textCW.getText()),
                Float.parseFloat(textGAS.getText()), Float.parseFloat(txtELEC.getText()), Float.parseFloat(textHEAT.getText()));
        ArrayList<Expense> l = new ArrayList<>();
        l.add(b);
        cont.addKeyWithList(a,l);
    }
});

堆:

Exception in thread "AWT-EventQueue-0" java.lang.NumberFormatException: For input string: ""
    at java.lang.NumberFormatException.forInputString(Unknown Source)
    at java.lang.Integer.parseInt(Unknown Source) …

我试图比较两个字符串,但我没有实现这一点.为什么？

#include <stdio.h>
#include <string.h>

int main(){
    float a = 1231.23123;
    char b[32];
    sprintf(b, "%f", a);
    printf("%s\n", b);
    char c[32] = "1231.23123";
    if (strcmp(c, b) == 0){
        printf("SUCCES\n");
    }
    else{
        printf("DIFFER\n");
    }
    return 0;
}

结果:

1231.231201
DIFFER

可能重复:
使用整数连接两个QStrings

我期待在QT中创建一个3个整数和一个c ++ stl字符串的字符串,我该怎么做？有谁知道？,找不到解释这个过程的东西？

这是我的代码是我在lsit中创建元素,但我想打印所有元素和他们的属性不仅名称:

void Window::listMovies(){
ui->listMovies->clear();
vector <Movie> all = ctrl->getAllMovies();
for(int i=0; i <(int) all.size();i++){
    QListWidgetItem*item = new QListWidgetItem(
                QString::fromStdString(all[i].getName()),ui->listMovies);
    item->setData(Qt::UserRole,QVariant::fromValue(all[i].getID()));

电影对象有1个字符串和3个整数变量.

可能重复:
什么是Java？:运算符被调用,它做了什么？

您好,我在理解这些代码时遇到了一些问题,有人可以帮我解决这个问题吗？

private Comparable elementAt( BinaryNode t ) {
    return t == null ? null : t.element;
}

我不明白是什么t == null ? null : t.element;意思.

您好我为什么要*** - EVAL/APPLY: too many arguments given to F使用嵌套列表参数进行函数调用.我无法理解,因为我通过了一个简单的嵌套列表.

(defun f (L) 
    (cond 
        ((NULL l) nil)
        ((listp (car L)) 
            (append (F(car L))) (F(cdr L) (car (F (car L)))))
        (T (list(car L)))
    )
)

(setq A '((1) 2 3))
(f A)