js select control implementation code_form effects

Implementation code:

Copy code The code is as follows:

Add text and value at the same time
Operation on text Operation on value
view
del1
del2
del3

Effect demonstration:

<select id="test11" size="5" style="width:50px"></select> <select id="test" style="width:50px"></select> <button onclick='test[test.length]=new Option("1","12");'>Add text and value at the same time</button> <button onclick='test.insertBefore(document.createElement("option")).innerText="2";'>Operation on text</button> <button onclick='test.appendChild(document.createElement("option")).setAttribute("value","3");'>Operation on value</button> <button onclick="alert(test.outerHTML)">view</button> <button onclick="test.removeChild(test.children[0])">del1</button> <button onclick="test.firstChild.removeNode()">del2</button> <button onclick="test[0]=null">del3</button>
[Ctrl A select all Note: If you need to introduce external Js, you need to refresh to execute ]