[javascript] Getting value GET OR POST variable using JavaScript?

How to get value of the get or post variable on page load using JavaScript?

The simplest technique:

If your form action attribute is omitted, you can send a form to the same HTML file without actually using a GET HTTP access, just by using onClick on the button used for submitting the form. Then the form fields are in the elements array document.FormName.elements . Each element in that array has a value attribute containing the string the user provided (For INPUT elements). It also has id and name attributes, containing the id and/or name provided in the form child elements.

// Captura datos usando metodo GET en la url colocar index.html?hola=chao
const $_GET = {};
const args = location.search.substr(1).split(/&/);
for (let i=0; i<args.length; ++i) {
    const tmp = args[i].split(/=/);
    if (tmp[0] != "") {
        $_GET[decodeURIComponent(tmp[0])] = decodeURIComponent(tmp.slice(1).join("").replace("+", " "));
        console.log(`>>${$_GET['hola']}`);
    }//::END if
}//::END for

Here is my answer for this given a string returnURL which is like http://host.com/?param1=abc&param2=cde. It's fairly basic as I'm beginning at JavaScript (this is actually part of my first program ever in JS), and making it simpler to understand rather than tricky.

Notes

• No sanity checking of values
• Just outputting to the console - you'll want to store them in an array or something

• this is only for GET, and not POST

  var paramindex = returnURL.indexOf('?');
  if (paramindex > 0) {
      var paramstring = returnURL.split('?')[1];
      while (paramindex > 0) {
          paramindex = paramstring.indexOf('=');
          if (paramindex > 0) {
              var parkey = paramstring.substr(0,paramindex);
              console.log(parkey)
              paramstring = paramstring.substr(paramindex+1) // +1 to strip out the =
          }
          paramindex = paramstring.indexOf('&');
          if (paramindex > 0) {
              var parvalue = paramstring.substr(0,paramindex);
              console.log(parvalue)
              paramstring = paramstring.substr(paramindex+1) // +1 to strip out the &
          } else { // we're at the end of the URL
              var parvalue = paramstring
              console.log(parvalue)
              break;
          }
      }
  }
  

You can only get the URI arguments with JavaScript.

// get query arguments
var $_GET = {},
    args = location.search.substr(1).split(/&/);
for (var i=0; i<args.length; ++i) {
    var tmp = args[i].split(/=/);
    if (tmp[0] != "") {
        $_GET[decodeURIComponent(tmp[0])] = decodeURIComponent(tmp.slice(1).join("").replace("+", " "));
    }
}

This is my first Answer in stackoverflow and my english is not good. so I can't talk good about this problem:)

I think you might need the following code to get the value of your or tags.

this is what you might need:

HTML

<input id="input_id" type="checkbox/text/radio" value="mehrad" />

<div id="writeSomething"></div>

JavaScript

function checkvalue(input , Write) {
  var inputValue = document.getElementById(input).value;
  if(inputValue !="" && inputValue !=null) { 
    document.getElementById(Write).innerHTML = inputValue;
  } else { 
    document.getElementById(Write).innerHTML = "Value is empty";
  }
}

also, you can use other codes or other if in this function like this:

function checkvalue(input , Write) {
  var inputValue = document.getElementById(input).value;
  if(inputValue !="" && inputValue !=null) { 
    document.getElementById(Write).innerHTML = inputValue;
    document.getElementById(Write).style.color = "#000";
  } else {
    document.getElementById(Write).innerHTML = "Value is empty";
  }
}

and you can use this function in your page by events like this:

<div onclick="checkvalue('input_id','writeSomthing')"></div>

I hope my code will be useful for you

Write by <Mehrad Karampour>

With little php is very easy.

HTML part:

<input type="text" name="some_name">

JavaScript

<script type="text/javascript">
    some_variable = "<?php echo $_POST['some_name']?>";
</script>

When i had the issue i saved the value into a hidden input:

in html body:

    <body>
    <?php 
    if (isset($_POST['Id'])){
      $fid= $_POST['Id']; 
    }
    ?>

... then put the hidden input on the page and write the value $fid with php echo

    <input type=hidden id ="fid" name=fid value="<?php echo $fid ?>">

then in $(document).ready( function () {

    var postId=document.getElementById("fid").value;

so i got my hidden url parameter in php an js.