如何在內容可編輯元素中設定插入符位置？

function setCaret() {
    var el = document.getElementById("editable");
    var range = document.createRange();
    var sel = window.getSelection();

    // Set the start position of the range at the beginning of the fifth character of the third line
    range.setStart(el.childNodes[2], 5);

    // Collapse the range to the start point
    range.collapse(true);

    // Set the selection to start at the start position of the range
    sel.removeAllRanges();
    sel.addRange(range);
}