JavaScript Feature Reference: localStorage Object Web Browser Support Test

1. Introduction

In this web page there are two web browser JavaScript feature support tests; 1.) a feature implementation test, and 2.) a feature capability test. First, the implementation test is run. The implementation test determines if the web browser recognizes the JavaScript localStorage object. The implementation test is a simple test for the presence of web browser support, and a definitive test for the absence of web browser support. If the web browser does not recognize the JavaScript localStorage object, the testing is stopped and the implementation test reports: Fail (no support): The web browser does not recognize the JavaScript localStorage object. The web browser does not support the JavaScript localStorage object.

If the web browser recognizes the JavaScript localStorage object, the capability test is run. The capability test determines if the web browser's implementation of the JavaScript localStorage object includes support for at least one localStorage object capability. The capability test is a more definitive, albeit not an all inclusive, test for the presence of web browser support. If the web browser's implementation of the JavaScript localStorage object includes support for the tested capability, the capability test reports: Pass (at least partial/possibly full support): The web browser recognizes the JavaScript localStorage object, and supports at least one localStorage object capability. The web browser at least partially/possibly fully supports the JavaScript localStorage object. Positive determination of full web browser support is beyond the scope of this test. If the web browser's implementation of the JavaScript localStorage object does not include support for the tested capability, the capability test reports: Pass/Fail (partial support): The web browser recognizes the JavaScript localStorage object, but does not support at least one localStorage object capability. The web browser partially supports the JavaScript localStorage object.

The web browser support test source code is shown in Section 2.1. The web browser support test source code is run in Section 2.2, which shows the web browser support test result.

1.1. localStorage Object Web Browser Support

Pass (at least partial/possibly full support): IE8+, ED12+, FF3.5+, SF4+, CH4+, OP10.50+.

1.2. Abbreviations

• IE = Internet Explorer.
• ED = Edge Legacy 12 - 18 (EdgeHTML based) and Edge 79+ (Chromium based).
• FF = Firefox.
• SF = Safari.
• CH = Chrome.
• OP = Opera.

2. localStorage Object Web Browser Support Test

2.1. Web Browser Support Test Source Code

<script>
if (window.localStorage){ // Identical to if (localStorage).
 localStorage.setItem("keyOne", "keyOne value");
 localStorage.setItem("keyTwo", "keyTwo value");
 localStorage.setItem("keyThree", "keyThree value");
 if (localStorage.length === 3){
  document.write("<p><b>Pass</b> (at least partial/possibly full support): The web browser recognizes the JavaScript <code>localStorage</code> object, and supports at least one <code>localStorage</code> object capability. The web browser at least partially/possibly fully supports the JavaScript <code>localStorage</code> object. Positive determination of full web browser support is beyond the scope of this test.</p>");
 } else {
  document.write("<p><b>Pass/Fail</b> (partial support): The web browser recognizes the JavaScript <code>localStorage</code> object, but does not support at least one <code>localStorage</code> object capability. The web browser partially supports the JavaScript <code>localStorage</code> object.</p>");
 }
} else {
 document.write("<p><b>Fail</b> (no support): The web browser does not recognize the JavaScript <code>localStorage</code> object. The web browser does not support the JavaScript <code>localStorage</code> object.</p>");
}
</script>

2.2. Web Browser Support Test Result

3. Resources And Additional Information

• JavaScript Feature Reference (learnwebcoding.com)