やりたいこと

UNIコード（0000～10ffff）の中に、漢字に割り当てられているのがいくつあるのか？正規表現を使い、調べてみようと思います。
調査に使用するのは次の通り

Code Point（0～1114111）を使う
漢字抽出に使う正規表現は/\p{sc=Han}/u

漢字総数、抽出コード

const arr = [];

for (let n = 0; n <= 1114111; n++) {
    let str = String.fromCodePoint(n);
	if (/\p{sc=Han}/u.test(str)) {
	    arr.push({
		    codepoint: n,
			kanji: str,
			length: str.length,
			unicode: `U+${n.toString(16)}`,
		})
	}
}

console.log(`漢字総数 = ${arr.length}`);

"漢字総数 = 99030" //結果

配列arr内、昇順10

for (let n = 0; n < 10; n++) console.log(arr.at(n));

// 結果
{
  codepoint: 11904,
  kanji: "⺀",
  length: 1,
  unicode: "U+2e80"
}
{
  codepoint: 11905,
  kanji: "⺁",
  length: 1,
  unicode: "U+2e81"
}
{
  codepoint: 11906,
  kanji: "⺂",
  length: 1,
  unicode: "U+2e82"
}
{
  codepoint: 11907,
  kanji: "⺃",
  length: 1,
  unicode: "U+2e83"
}
{
  codepoint: 11908,
  kanji: "⺄",
  length: 1,
  unicode: "U+2e84"
}
{
  codepoint: 11909,
  kanji: "⺅",
  length: 1,
  unicode: "U+2e85"
}
{
  codepoint: 11910,
  kanji: "⺆",
  length: 1,
  unicode: "U+2e86"
}
{
  codepoint: 11911,
  kanji: "⺇",
  length: 1,
  unicode: "U+2e87"
}
{
  codepoint: 11912,
  kanji: "⺈",
  length: 1,
  unicode: "U+2e88"
}
{
  codepoint: 11913,
  kanji: "⺉",
  length: 1,
  unicode: "U+2e89"
}

配列arr内、降順10

for (let n = 0; n < 10; n++) console.log(arr.at(~n));

// 結果
{
  codepoint: 205743,
  kanji: "𲎯",
  length: 2,
  unicode: "U+323af"
}
{
  codepoint: 205742,
  kanji: "𲎮",
  length: 2,
  unicode: "U+323ae"
}
{
  codepoint: 205741,
  kanji: "𲎭",
  length: 2,
  unicode: "U+323ad"
}
{
  codepoint: 205740,
  kanji: "𲎬",
  length: 2,
  unicode: "U+323ac"
}
{
  codepoint: 205739,
  kanji: "𲎫",
  length: 2,
  unicode: "U+323ab"
}
{
  codepoint: 205738,
  kanji: "𲎪",
  length: 2,
  unicode: "U+323aa"
}
{
  codepoint: 205737,
  kanji: "𲎩",
  length: 2,
  unicode: "U+323a9"
}
{
  codepoint: 205736,
  kanji: "𲎨",
  length: 2,
  unicode: "U+323a8"
}
{
  codepoint: 205735,
  kanji: "𲎧",
  length: 2,
  unicode: "U+323a7"
}
{
  codepoint: 205734,
  kanji: "𲎦",
  length: 2,
  unicode: "U+323a6"
}

配列arr内、ランダム10

for (let n = 0; n < 10; n++) {
    let r = Math.floor(Math.random() * arr.length);
    console.log(arr.at(r));
}

// 結果
{
  codepoint: 157400,
  kanji: "𦛘",
  length: 2,
  unicode: "U+266d8"
}
{
  codepoint: 187686,
  kanji: "𭴦",
  length: 2,
  unicode: "U+2dd26"
}
{
  codepoint: 37145,
  kanji: "鄙",
  length: 1,
  unicode: "U+9119"
}
{
  codepoint: 136452,
  kanji: "𡔄",
  length: 2,
  unicode: "U+21504"
}
{
  codepoint: 147258,
  kanji: "𣼺",
  length: 2,
  unicode: "U+23f3a"
}
{
  codepoint: 27462,
  kanji: "歆",
  length: 1,
  unicode: "U+6b46"
}
{
  codepoint: 141714,
  kanji: "𢦒",
  length: 2,
  unicode: "U+22992"
}
{
  codepoint: 143382,
  kanji: "𣀖",
  length: 2,
  unicode: "U+23016"
}
{
  codepoint: 18532,
  kanji: "䡤",
  length: 1,
  unicode: "U+4864"
}
{
  codepoint: 21068,
  kanji: "剌",
  length: 1,
  unicode: "U+524c"
}

まとめ

UNIコード内に割り当てられている漢字総数 = 99030
length が2の漢字などは、正直全く読めない
降順10では、環境依存なだけなのか？それとも未割当なのか？自分の所では「□」表示が多い（スマホだと、もっと「□」表示が多いかも）

以上、まとめでした。
その他、

こんなのあるよ
もっと簡潔に出来るよ
それ間違ってるよ

などありましたら、コメントでお待ちしております。