多个字段：提交后记住输入值

I have a multiple field input and I want to remember the input values after submitting it , how can I do that using php or maybe another language if it is possible? I have this input:

<input type="text" name="passport[]"  class="form-control" aria-describedby="basic-addon1"required/>

I have tried something like this :

value="<?php if(isset($_POST['passport'])) { echo $_POST['passport'][$i]; } ?>" 

but nothing works.

You can use browser local storage to keep the value after form submission.

<form method="post" action="" onSubmit="return saveElement();">
   <input type="text" name="passport[]"  id="password"/>
   <input type="submit" name="submit" value="save"/>
</form>
<script type="text/javascript">
 document.getElementById("password").value = localStorage.getItem("password");
 function saveElement() {
    var passValue = document.getElementById("password").value;
    if (passValue == "") {
        alert("Please enter a password first!");
        return false;
    }
    localStorage.setItem("password", passValue);
    location.reload();
    return false;
 }
</script>