How can I store options tags in sessionStorage?

问题:

This is my HTML:

<select>
   <option value="val1">Text1</option>
   <option value="val2">Text2</option>
   <option value="val3">Text3</option>
   <option value="val4">Text4</option>
</select>

It is being dynamically populated via $.ajax()

I need to make a function that will place "val" in key and Text in "value" in the sessionStorage, as the object reference. How can I achieve this?

How would it be iterated via index?

My try:

document.getElementsByClassName('next')[0].addEventListener('click', function() {
    sessionStorage.setItem(option.value, option.innerText);
});

.addEventListener() is not firing at all . . . why?

Also, I need it loaded afterwards. How do I do it? Do I use .trigger()?

回答1:

Just like this:

var btn = document.querySelector(".next");
var test = document.querySelector(".test");

btn.addEventListener("click", function(){
  // Get a reference to the select's options
  var options = document.querySelectorAll("option");

  // Loop through the options and store the value and text in sessionStorage:
  for(var i = 0; i < options.length; ++i){
    sessionStorage.setItem(options[i].getAttribute("value"), options[i].textContent);
  }
});

test.addEventListener("click", function(){

  // Now, just to show how to get the values out of sessionStorage:
  for (var i = 0; i < sessionStorage.length; i++){
    alert(sessionStorage.getItem(sessionStorage.key(i)));
  }

});

<select>
   <option value="val1">Text1</option>
   <option value="val2">Text2</option>
   <option value="val3">Text3</option>
   <option value="val4">Text4</option>
</select>
<button class="next">Next</button>

<button class="test">Test</button>

This code won't work, here in the Stack Overflow snippet environment, but you can see it work here.