Convert Uppercase And Lowercase In Javascript

December 27, 2023 Post a Comment

I want to make a code that converts uppercase and lowercase in Javascript. For example, 'Hi, Stack Overflow.' ----> 'hI, sTACK oVERFLOW' How can I do it?

Solution 1:

You could run over each character, and then covert it to lowercase if it's in uppercase, to uppercase if it's in lowercase or take it as is if it's neither (if it's a comma, colon, etc):

str = 'Hi, Stack Overflow.';
res = '';
for (var i = 0; i < str.length; ++i) {
    c = str[i];
  if (c == c.toUpperCase()) {
    res += c.toLowerCase();
  } elseif (c == c.toLowerCase()) {
    res += c.toUpperCase();
  } else {
    res += c;
  }
}

Solution 2:

You can try this simple solution using map()

var a = 'Hi, Stack Overflow!'var ans = a.split('').map(function(c){
  return c === c.toUpperCase()
  ? c.toLowerCase()
  : c.toUpperCase()
}).join('')

console.log(ans)

Solution 3:

<!DOCTYPE html><html><head><title>hello</title><scriptsrc="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script></head><body><script>
$(document).ready(function(){
    var x = 'Hi, Stack Overflow.';

    alert(caseAlter(x));

    functioncaseAlter(txt){
        var output = "";

        for(var i = 0; i < txt.length; i++){
            if(txt[i] == txt[i].toUpperCase()){
                output += txt[i].toLowerCase();
            }else{
                output += txt[i].toUpperCase();
            }           
        }

        return output;
    }

});
</script></body></html>

Solution 4:

var hi = 'Hi, Stack Overflow.';

var hI = hi.split("");
for(var i=0;i<hI.length;i++){
if(hI[i] == hI[i].toLowerCase())hI[i]  = hI[i].toUpperCase();
elseif(hI[i] == hI[i].toUpperCase())hI[i] = hI[i].toLowerCase();
} 
hI = hI.join("");
alert(hI);
//'hI, sTACK oVERFLOW'

Solution 5:

var input = 'Hi, Stack Overflow.'
var arr = input.split(' ');

alert(arr);
var output = arr.map(function(elem){

  return (elem[0].toLowerCase() + elem.substring(1,elem.length).toUpperCase());

});

alert(output.join());

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