How can I validate a sentence using PHP and JavaScript?

I am currently trying to validate if the sentence a user enters matches the expected sentence. The expected sentence is stored in a PHP variable $rebuiltSentence, for example 'the cat sat'.

The problem is that when I try to call my JavaScript function formSubmit() I need to give it the sentence to check, therefore ideally I would call formSubmit($rebuiltSentence). I think this won't work because it thinks it is being passed several separate strings.

Here is what I've got:

//sentence.php

<input type='button' value='Submit' onClick=formSubmit('$rebuiltSentence')

and

//validate.js
function formSubmit(correct)
{
var contents = document.getElementById('sentenceBuilder').value;
if(contents==correct){

 alert('The Sentences Match');
}else{
 alert('The Sentences Dont Match');
}

window.location.reload(true);
}

Any ideas how I can solve this?

From stackoverflow

• It looks like you are passing the string $rebuiltSentence rather than the sentence that this parameter holds in PHP.

  Change to the follwoing

  //sentence.php

  echo "<input type='button' value='Submit' onClick=formSubmit('".$rebuiltSentence."')";
  

  and it will echo the content of $rebuiltSentence.

  Greg : This won't work if $rebuiltSentence contains a single quote, and won't be right if it contains, e.g. an ampersand.

• You should quote the attribute and escape it properly:

  echo '<... onClick="formSubmit(' . htmlspecialchars(json_encode($rebuiltSentence)) . ');">'
  

• You could add the sentence as a hidden field to validate against.

  //sentence.php
  
  <input type='hidden' id=rebuiltSentence value='$rebuildSentence'>
  <input type='button' value='Submit' onClick=formSubmit()>
  

  and to validate you could then easily use

  //validate.js
  function formSubmit()
  {
    var contents = document.getElementById('sentenceBuilder').value;
    var correct  = document.getElementById('rebuiltSentence').value;
    if(contents==correct)
    {
      alert('The Sentences Match');
    }else{
      alert('The Sentences Dont Match');
    }
  
    window.location.reload(true);
  }