js中字符串转base64和base64转字符串

var str = '坂井泉水';

  //console.log(encodeURI(str));
  //console.log(btoa(encodeURI(str)));

  //console.log(atob(btoa(encodeURI(str))));
  //console.log(decodeURI(atob(btoa(encodeURI(str)))));


  //字符串转base64
  function encode(str){
    // 对字符串进行编码
    var encode = encodeURI(str);
    // 对编码的字符串转化base64
    var base64 = btoa(encode);
    return base64;
  }

  // base64转字符串
  function decode(base64){
      // 对base64转编码
      var decode = atob(base64);
      // 编码转字符串
      var str = decodeURI(decode);
      return str;
  }

  console.log(encode(str));
  console.log(decode(encode(str)));