What if you change the parameters inside the function, and then use return to return the parameters, but display the original input parameters?

clipboard.png
just a few weeks after contact with javascript, I encountered a question about Caesar"s password, so I started to write it, but I haven"t finished it yet. It is found that although the parameters have been changed inside the function, what should I do if I want to return the parameters that have been changed (to achieve the effect of letter shift), but return the original parameters as they are?

Javascript
Mar.16,2021 
str = str.replace...

as a matter of fact, there is no need to move back and forth between charCodeAt/fromCharCode. It can be handled completely and transferred to Unification

. 
function rot13(str){
    //    Unicode
    var empty = Array.prototype.map.call(str,function(s){return s.charCodeAt(0)})
    // 
    .map(function(num){
        // left
        if(num >=65 && num <= 77){
            return num + 13;
        // right
        } else if(num >= 78 && num <= 90){
            return num;
        // 
        } else {
            return num;
        }
    });
    //  Unicode 
    return String.fromCharCode.apply(null, empty);
}
After

str performs replace, you need to assign the obtained content back to str

    In line 9 of
  1. code, do not use in , in to determine whether an object has an attribute, and not to judge whether an array contains an element. Use includes instead;
    2. Line 10 of
  2. code uses str = str.replace to reassign str ; 
function rot13 (str) {
  var empty = [];
  for (var i = 0; i < str.length; iPP) {
    empty.push(str.charCodeAt(i))
  }
  var left = empty.filter(function (x) {return x >= 65 && x <= 77})
  var right = empty.filter(function (y) {return y >= 78 && y <= 90})
  for (var j = 0; j < str.length; jPP) {
    if (left.includes(str.charCodeAt(j))) { // includes
      str = str.replace(str[j], String.fromCharCode(str.charCodeAt(j) + 13)) // 
    }
  }
  return str
}

Previous: If you have doubts about the interpretation of the events npm module, please help sort out the train of thought.

Next: Django is created in batches using bulk_create, and the returned objects are not contended (primary key)

css mysql arrays josn react html typescript webpack npm sass R objective-c .net sql-server jquery python-3.x angularjs django angular excel regex iphone ajax linux xml pandas vba spring database wordpress string wpf xcode windows bash postgresql oracle multithreading eclipse list firebase algorithm macos forms image scala visual-studio azure bootstrap spring-boot react-native python-2.7 docker performance function winforms matlab powershell apache dataframe api sqlite numpy rest shell selenium flutter dart maven loops qt swing android-studio csv express file class tensorflow sorting codeigniter perl
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1e6907f-45534.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1e6907f-45534.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
Need Help?