如何在不使用任何正則表達式/內置 function 如 split、join、indexOf 等的情況下將大寫字母移動到前面

Question

function moveCapLetter(moveCap) {
  let upr = /[A-Z]/g;
  let ul = moveCap.match(upr);

  for (let i = 0; i < ul.length; i++) {
    let m = moveCap.length;
    let indx = moveCap.indexOf(ul[i]);
    moveCap =
      moveCap.substring(0, indx) + moveCap.substring(indx + 1, moveCap.length);
  }
  moveCap = ul.join("") + moveCap;
  return moveCap;
}

Answer 1

我想出的唯一方法是使用toUpperCase （否則我們如何檢查）和 concat 分別將其轉換為uppercase后測試它是uppercase還是lowercase 。

 function moveCapLetter(str) { let upper = "", lower = ""; for (let i = 0; i < str.length; ++i) { if (str[i] === str[i].toUpperCase()) { upper += str[i]; } else lower += str[i]; } return (upper += lower); } const result = moveCapLetter("eNviRonMEnT"); console.log(result);