Is there a way to detect if a user has not answered an input?-CodePudding

I am making a name picker and I want to detect if your user has input a name or if they are just messing with the website. Is there a way to do this? Code:

<html>
<textarea id="names"></textarea>
<input type="submit" value="Pick" onclick="onClick(this)">
<p id="chosen"></p>
</html>
<script>
function onClick(x) {
//Your code
}
</script>

CodePudding user response：

The getNames() method is called for the <input> element to check for value when it submits, and a value is returned after the value inside the <textarea> element is checked.

/* This helper method checks whether the login has been made or not. */
function isNameEmpty(){
   var name = document.getElementById("names");
   
   if(name.value.length != 0){
      console.log(name.value);
      return false;
   }
   else{
      console.log('No value was entered.');
      return true;
   }
}

/* This submit method is used to return the entered name. */
function getNames(){
  if(!isNameEmpty()){
    return document.getElementById("names").value;
  }
  else{
    alert('No value was entered.');
    return '';
  }
}

<textarea id="names"></textarea>
<input type="submit" value="Pick" onclick="return getNames();">
<p id="chosen"></p>

References

Add onclick function to a submit button

CodePudding user response：

you can change the textarea to input tag and you can use browser built in attributes like type= text min max length etc.

otherwise you should write a function that reads and evaluates the input value of the textarea