js简单实现复制

<input type="text" id="text-box" size="20" value="Hello world!">
<button onclick="selectText()">Select text</button>复制代码

function selectText() {
  const input = document.getElementById('text-box');
  input.focus();
  input.select();
  input.setSelectionRange(0, 5);
 document.execCommand('copy');
}复制代码

复制js库

命令文档