Question

我正在开发一个添加更多按钮的表单。单击按钮时，将生成一组字段。我已经为此完成了javascript验证，如果所有添加的字段为空则提醒消息。代码是：

var n = document.getElementById('cnnumrows').value, i;

if ( frm_add_announcement.sublink[1].checked == true ) {
    for(i=1; i<=n; i++) {
        if ( (document.getElementById('url'+i).value.trim()=="") && ( document.getElementById("document"+i).files.length == 0 ) ) {   
            alert("Enter a url/upload a file");
            document.getElementById('captionurl').focus();
            return false;   
        }
    }
}

如果插入了任何字段，则必须更改此值，无需警报，如果所有字段都为空警报。任何建议

Answer 1

试试这个：

#include <iostream> 
#include <chrono>
#include <future>
#include <thread>

class MyThread {
private:
    std::atomic<bool> exit;
    std::thread t;
public:
    MyThread() : exit(false) {
        t = std::thread(std::ref(*this));
    }
    ~MyThread() {
        exit.store(true, std::memory_order_relaxed);
        if (t.joinable()) {
            t.join();
        }
    }
    void operator()() {
        while (!exit.load(std::memory_order_relaxed)) {
            std::cout << "."; // some more meaningful work here
            std::this_thread::sleep_for(std::chrono::seconds(1));
        }
    }
};

int main() {
    MyThread t;
    std::cin.get();
    return 0;
}

Answer 2

<script type="text/javascript">
  document.form1.studentName.focus();
  function validateform(){
  var sname=document.form1.studentName.value;  
  var sclass=document.form1.studentClass.value;  
  var semail=document.form1.studentemail.value;  
  var sphone=document.form1.studentphone.value;
  var flag=false;
  var phoneno = /^\d{7}$/;
  if(sname==null || sname==""){
    alert("student name is empty\nFormate: XXXXXXXXX");
    flag=false;
    return false;
 }else {
   flag=true;
 }
 if(sclass==null || sclass==""){
   alert("student class is empty\nFormate: XXXxx");
   flag=false;
   return false;
 }else {
   flag=true;
 }
 if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(semail)) {  
    flag=true;
 }else{
    alert("student e-mail formate error \nFormate: example@example.xxx\n               example@example.xx");
    flag=false;
    return false;
 }
 if(sphone.match(phoneno)){  
   flag=true;
 }else{
    alert("student phone must contain atleast 7 digits\nFormate: XXXXXXX");
    flag=false;
    return false;
 }
   return flag;
 };
</script>

检查是否使用javascript在表单中插入了值

2 个答案: