子である要素のうち、最初のもの？を返す。→●

document.firstElementChild＝ ／[Edge]

version[string]＝

title[string]＝

lang[string]＝

translate[boolean]＝true

dir[string]＝

hidden[boolean]＝false

accessKey[string]＝

draggable[boolean]＝false

spellcheck[boolean]＝true

autocapitalize[string]＝

contentEditable[string]＝inherit

isContentEditable[boolean]＝false

inputMode[string]＝

offsetParent[object]＝null

offsetTop[number]＝0

offsetLeft[number]＝0

offsetWidth[number]＝1185

offsetHeight[number]＝14045

style[object]＝[object CSSStyleDeclaration]

innerText[string]＝DHTML： documentオブジェクト　 編集：2021.05.15 by T.A. ブラウザ･ウィンドウ内のHTML文書を表す。 内容[Edge]。[･･･

outerText[string]＝DHTML： documentオブジェクト　 編集：2021.05.15 by T.A. ブラウザ･ウィンドウ内のHTML文書を表す。 内容[Edge]。[･･･

onbeforexrselect[object]＝null

onabort[object]＝null

onblur[object]＝null

oncancel[object]＝null

oncanplay[object]＝null

oncanplaythrough[object]＝null

onchange[object]＝null onclick[object]＝null onclose[object]＝null oncontextmenu[object]＝null oncuechange[object]＝null ondblclick[object]＝null ondrag[object]＝null ondragend[object]＝null ondragenter[object]＝null ondragleave[object]＝null ondragover[object]＝null ondragstart[object]＝null ondrop[object]＝null ondurationchange[object]＝null onemptied[object]＝null onended[object]＝null onerror[object]＝null onfocus[object]＝null onformdata[object]＝null oninput[object]＝null oninvalid[object]＝null onkeydown[object]＝null onkeypress[object]＝null onkeyup[object]＝null onload[object]＝null onloadeddata[object]＝null onloadedmetadata[object]＝null onloadstart[object]＝null onmousedown[object]＝null onmouseenter[object]＝null onmouseleave[object]＝null onmousemove[object]＝null onmouseout[object]＝null onmouseover[object]＝null onmouseup[object]＝null onmousewheel[object]＝null onpause[object]＝null onplay[object]＝null onplaying[object]＝null onprogress[object]＝null onratechange[object]＝null onreset[object]＝null onresize[object]＝null onscroll[object]＝null onseeked[object]＝null onseeking[object]＝null onselect[object]＝null onstalled[object]＝null onsubmit[object]＝null onsuspend[object]＝null ontimeupdate[object]＝null ontoggle[object]＝null onvolumechange[object]＝null onwaiting[object]＝null onwebkitanimationend[object]＝null onwebkitanimationiteration[object]＝null onwebkitanimationstart[object]＝null onwebkittransitionend[object]＝null onwheel[object]＝null onauxclick[object]＝null ongotpointercapture[object]＝null onlostpointercapture[object]＝null onpointerdown[object]＝null onpointermove[object]＝null onpointerup[object]＝null onpointercancel[object]＝null onpointerover[object]＝null onpointerout[object]＝null onpointerenter[object]＝null onpointerleave[object]＝null onselectstart[object]＝null onselectionchange[object]＝null onanimationend[object]＝null onanimationiteration[object]＝null onanimationstart[object]＝null ontransitionrun[object]＝null ontransitionstart[object]＝null ontransitionend[object]＝null ontransitioncancel[object]＝null oncopy[object]＝null oncut[object]＝null onpaste[object]＝null dataset[object]＝[object DOMStringMap] nonce[string]＝ autofocus[boolean]＝false tabIndex[number]＝-1 attachInternals[function]＝function attachInternals() { [native code] } blur[function]＝function blur() { [native code] } click[function]＝function click() { [native code] } focus[function]＝function focus() { [native code] } onpointerrawupdate[object]＝null enterKeyHint[string]＝ namespaceURI[string]＝http://www.w3.org/1999/xhtml prefix[object]＝null localName[string]＝html tagName[string]＝HTML id[string]＝ className[string]＝ classList[object]＝ slot[string]＝ attributes[object]＝[object NamedNodeMap] shadowRoot[object]＝null part[object]＝ assignedSlot[object]＝null innerHTML[string]＝ DHTML： d･･･ ELEMENT_NODE[number]＝1 ATTRIBUTE_NODE[number]＝2 TEXT_NODE[number]＝3 CDATA_SECTION_NODE[number]＝4 ENTITY_REFERENCE_NODE[number]＝5 ENTITY_NODE[number]＝6 PROCESSING_INSTRUCTION_NODE[number]＝7 COMMENT_NODE[number]＝8 DOCUMENT_NODE[number]＝9 DOCUMENT_TYPE_NODE[number]＝10 DOCUMENT_FRAGMENT_NODE[number]＝11 NOTATION_NODE[number]＝12 DOCUMENT_POSITION_DISCONNECTED[number]＝1 DOCUMENT_POSITION_PRECEDING[number]＝2 DOCUMENT_POSITION_FOLLOWING[number]＝4 DOCUMENT_POSITION_CONTAINS[number]＝8 DOCUMENT_POSITION_CONTAINED_BY[number]＝16 DOCUMENT_POSITION_IMPLEMENTATION_SPECIFIC[number]＝32 appendChild[function]＝function appendChild() { [native code] } cloneNode[function]＝function cloneNode() { [native code] } compareDocumentPosition[function]＝function compareDocumentPosition() { [native code] } contains[function]＝function contains() { [native code] } getRootNode[function]＝function getRootNode() { [native code] } hasChildNodes[function]＝function hasChildNodes() { [native code] } insertBefore[function]＝function insertBefore() { [native code] } isDefaultNamespace[function]＝function isDefaultNamespace() { [native code] } isEqualNode[function]＝function isEqualNode() { [native code] } isSameNode[function]＝function isSameNode() { [native code] } lookupNamespaceURI[function]＝function lookupNamespaceURI() { [native code] } lookupPrefix[function]＝function lookupPrefix() { [native code] } normalize[function]＝function normalize() { [native code] } removeChild[function]＝function removeChild() { [native code] } replaceChild[function]＝function replaceChild() { [native code] } addEventListener[function]＝function addEventListener() { [native code] } dispatchEvent[function]＝function dispatchEvent() { [native code] } removeEventListener[function]＝function removeEventListener() { [native code] }