如何在Javascript中恢复插入符号的位置？

const element = document.activeElement;
const startPos = element.selectionStart;

const symbol = '插入符号';
const newValue = element.value.substring(0, startPos) + symbol + element.value.substring(startPos);

element.value = newValue;

function insertSymbol() {
  const element = document.activeElement;
  const startPos = element.selectionStart;
  const symbol = '插入符号';
  const newValue = element.value.substring(0, startPos) + symbol + element.value.substring(startPos);
  element.value = newValue;
}