字符串大小写字母转换

[1684838553]

let str = 'aBcDeFgH'
let arr = []
for(let item of str) {
  if (item === item.toUpperCase()) {
    item = item.toLowerCase()
  } else {
    item = item.toUpperCase()
  }
  arr.push(item)
}
let newStr = arr.join('')
console.log(newStr)
// AbCdEfGh