Question

我想知道在StdMark＆gt; 50时如何使用字符串s1来打印成功。我需要在单向选择中这样做，换句话说，不使用else语句。

#include <iostream>
#include <string>
using namespace std;

int main() 
{
    int StdMark;
    string s1;
    s1="succuss";
    cout <<"Enter The grade:"<<endl;
    cin >>StdMark;
    if(StdMark<50)
    {
        cout<<"fail";
    }
    return 0;
}

Answer 1

我找到了问题的答案：

using System;
using System.Collections.ObjectModel;
using System.Windows;

namespace ListBoxUpdate
{
    public partial class Window1 : Window
    {
        public ObservableCollection<StringWrapper> Strings { get; set; }

        public class StringWrapper 
        {
            public string Content { get; set; }

            public StringWrapper(string content)
            {
                this.Content = content;
            }

            public static implicit operator StringWrapper(string content)
            {
                return new Window1.StringWrapper(content);
            }
        }

        public Window1()
        {
            InitializeComponent();

            this.Strings = new ObservableCollection<StringWrapper>(new StringWrapper[] { "one", "two", "three" });
            this.DataContext = this;
        }

        void HandleButtonClick(object sender, RoutedEventArgs e)
        {
            string text = "";

            for (int i = 0; i < Strings.Count; i++) {
                text += Strings[i].Content + Environment.NewLine;
            }

            textBlock.Text = text;
        }
    }
}

Answer 2

如果您不想使用if / else，则有以下几种选择：

使用?:三元运算符：

#include <iostream>
#include <string>

using namespace std;

int main()
{
    int StdMark;
    cout << "Enter The grade:" << endl;
    cin >> StdMark;
    cout  << (StdMark < 50) ? "fail" : "success";
    return 0;
}

声明包含"success"和"fail"的2元素字符串数组，然后使用<运算符的输出作为该数组的索引：< / p>

#include <iostream>
#include <string>

using namespace std;

int main()
{
    const char* str[2] = {"success", "fail"};
    int StdMark;
    cout << "Enter The grade:" << endl;
    cin >> StdMark;
    cout  << str[StdMark < 50];
    return 0;
}

在单向选择中使用字符串（if语句）

2 个答案: