实现函数传入person_first_name返回驼峰personFirstName

下划线转驼峰函数封装

let testStr = 'name_firstname_secondname'
function toUp(str) {
  let newStr = ''
  let arr = str.split('_') //先用字符串分割成数组
  arr.forEach((item, index) => {
    if (index > 0) {
      return newStr += item.replace(item[0], item[0].toUpperCase())
    } else {
      return newStr += item
    }
  })
  return newStr
}

toUp(testStr)
console.log("原先的:", testStr, "新来的:", toUp(testStr))

//原先的: name_firstname_secondname 新来的: nameFirstnameSecondname

function toHump(name) {
  return name.replace(/\_(\w)/g, function(all, letter){
    console.log('匹配到的值：',all,'下划线后面的值：',letter)
    return letter.toUpperCase();
  });
}

let ak = 'name_firstname_ij';
console.log(toHump(ak));

//nameFirstnameIj