Storage

Интерфейс Storage из Web Storage API предоставляет доступ для session storage или local storage для конкретного домена, позволяя вам для примера добавлять, изменять или удалять сохранённые элементы данных.

If you want to manipulate the session storage for a domain, you call Window.sessionStorage method; If you want to manipulate the local storage for a domain, you call Window.localStorage.

Properties

Storage.length Только для чтения

Returns an integer representing the number of data items stored in the Storage object.

Methods

Storage.key()

When passed a number n, this method will return the name of the nth key in the storage.

Storage.getItem()

When passed a key name, will return that key's value.

Storage.setItem()

When passed a key name and value, will add that key to the storage, or update that key's value if it already exists.

Storage.removeItem()

When passed a key name, will remove that key from the storage.

Storage.clear()

When invoked, will empty all keys out of the storage.

Examples

Here we access a Storage object by calling localStorage. We first test whether the local storage contains data items using !localStorage.getItem('bgcolor'). If it does, we run a function called setStyles() that grabs the data items using localStorage.getItem() and uses those values to update page styles. If it doesn't, we run another function, populateStorage(), which uses localStorage.setItem() to set the item values, then runs setStyles().

if(!localStorage.getItem('bgcolor')) {
  populateStorage();
} else {
  setStyles();
}

function populateStorage() {
  localStorage.setItem('bgcolor', document.getElementById('bgcolor').value);
  localStorage.setItem('font', document.getElementById('font').value);
  localStorage.setItem('image', document.getElementById('image').value);

  setStyles();
}

function setStyles() {
  var currentColor = localStorage.getItem('bgcolor');
  var currentFont = localStorage.getItem('font');
  var currentImage = localStorage.getItem('image');

  document.getElementById('bgcolor').value = currentColor;
  document.getElementById('font').value = currentFont;
  document.getElementById('image').value = currentImage;

  htmlElem.style.backgroundColor = '#' + currentColor;
  pElem.style.fontFamily = currentFont;
  imgElem.setAttribute('src', currentImage);
}

Specifications

Browser compatibility

All browsers have varying capacity levels for both localStorage and sessionStorage. Here is a detailed rundown of all the storage capacities for various browsers.

See also

Using the Web Storage API