CODEWITHSUNDEEP
javascript
Tiago Sa
Tiago Sa

Reputation: 87

How to convert lowercase string to uppercase string without toUppercase() function

function alpha()
{
    var a=prompt("Enter String: ");

    for(var b=[i=0];c=a.charCodeAt(i);)
    {
        b[i++]=String.fromCharCode(c|(c>96 && c<123));
    }
    alert(b.join(""))
}
console.log(alpha());

So far some letters in the code change when I run this but for some reason it is not changing the string characters to all uppercase. (Example of output; I type "hi" into the prompt and the alert outputs "i" so the h disappears for some reason.

Upvotes: 2

Views: 4814

Answers (7)

Dileep yadav
Dileep yadav

Reputation: 1

// code for change the string to lower case to upper case

const upperCase = ()=>{

    let welcome = prompt("Enter your string");
let upper = '';
for(let i=0; i<welcome.length;i++){
    code =  welcome.charCodeAt(i);

   if(code >= 97 && code <= 122){
    let co = code-32;
    console.log(co);
    upper += String.fromCharCode(co);
   }
   else
   {
    upper +=String.fromCharCode(code) ;
   }
   console.log(upper);
}
}

Upvotes: 0

nnnnnn
nnnnnn

Reputation: 150078

Here's a way to implement it without calling any functions at all:

function myToUpper(string) {
  var map = { a: 'A', b: 'B', c: 'C', d: 'D', e: 'E', f: 'F', g: 'G', h: 'H', i: 'I', j: 'J', k: 'K', l: 'L', m: 'M', n: 'N', o: 'O', p: 'P', q: 'Q', r: 'R', s: 'S', t: 'T', u: 'U', v: 'V', w: 'W', x: 'X', y: 'Y', z: 'Z' }

  var output = ''
  for (var i = 0; i < string.length; i++)
    output += map[string[i]] || string[i]

  return output
}

console.log( myToUpper('ABCdefGHIjkl123.') )   // 'ABCDEFGHIJKL123.'

Upvotes: 0

nnnnnn
nnnnnn

Reputation: 150078

Just for interest's sake, here's a way to do it in one statement without arrays or a loop (at least, not an explicit loop):

var input = 'ABCdefGHIjkl123.'  // or you could prompt("Enter String: ")

var output = input.replace(/[a-z]/g, function(m) {
  return String.fromCharCode(m.charCodeAt(0) - 32)
})

console.log(output)

Upvotes: 2

jakeehoffmann
jakeehoffmann

Reputation: 1419

Here's what I would do.

function alpha() {
  var a = prompt("Enter string: ");

  var upper = a.split('').map((e) => e.charCodeAt(0) > 96 && e.charCodeAt(0) < 123 ? String.fromCharCode(e.charCodeAt(0) - 32) : e);

  return upper.join('');
}

console.log(alpha());

Upvotes: 2

Tyler
Tyler

Reputation: 986

Since this is a learning objective, I will only described a means to do this and let you try to figure it out using this answer as a guideline.

first you want to loop through the characters in string. for each character you would want some code to turn it into a capital letter, assuming it is a letter. finally you want to hold the capitalized letters in a variable.

This link may help for UTF-8 charcodes. Even if you aren't using utf-8, it may give you some ideas. http://www.utf8-chartable.de/

Upvotes: 1

gyre
gyre

Reputation: 16777

As Barmar mentioned in the comments above:

Subtract 32 from the character code if the character is between 97 and 123.

You can make your looping logic a little clearer with a split-map-join combination.

Since you can also compare single-character strings in JavaScript, like 'a' < 'b', this can further reduce the amount of code needed to handle the conversion of character codes.

function alpha (s) {
  return s.split('').map(function (c) {
    return 'a' <= c && c <= 'z' ? String.fromCharCode(c.charCodeAt(0) - 32) : c
  }).join('')
}

console.log(
  alpha(prompt("Enter String: "))
)

Upvotes: 2

user1531038
user1531038

Reputation: 266

function alpha()
{
    var a=prompt("Enter String: ");
    var output="";
    for(var x=0;x<a.length;x++)
            output+=String.fromCharCode(a.charCodeAt(x)>96 && a.charCodeAt(x)<123 ? a.charCodeAt(x)-32: a.charCodeAt(x))
    return output;
}
console.log("--" + alpha());

Just get the ascii code for each char, and if it ranges between 97 to 122 ( a to z ) deduct 32 from val to get the corresponding upper case char. Hope this helps.

Upvotes: 3

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