Converting First Charcter of String to Upper Case

Question

I have JavaScript Array that store String variable in it. I have tried below code that help me to convert Javascript variable to uppercase letter,

<html>
<body>

    <p id="demo"></p>

    <button onclick="toUppar()">Click Here</button>

    <script>
    Array.prototype.myUcase=function()
    {
        for (i=0;i<this.length;i++)
          {
          this[i]=this[i].toUpperCase();
          }
    }

    function toUppar()
    {
        var numArray = ["one", "two", "three", "four"];
        numArray.myUcase();
        var x=document.getElementById("demo");
        x.innerHTML=numArray;
    }
    </script>

</body>
</html>

but i want to convert only first character of Javascript Variable to Upper case.

Desired output : One,Two,Three,Four

`@thgaskell` i need to with JavaScript array not directly for java script variable. — Vijay, Aug 31 '13 at 09:26
In that case take a look at [`Array.map`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map) :) — thgaskell, Aug 31 '13 at 12:08

score 5 · Answer 1 · edited Apr 09 '18 at 15:45

5

If you need the upper case for presentation to your views, you can simply use css for do so!

div.capitalize:first-letter {
  text-transform: capitalize;
}

here is the complete fiddle example: http://jsfiddle.net/wV33P/1/

edited Apr 09 '18 at 15:45

NearHuscarl

66,950
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answered Aug 31 '13 at 09:36

cl0udw4lk3r

2,663
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score 4 · Answer 2 · edited May 23 '17 at 12:25

Use this extension (as per previous SO-answer):

String.prototype.first2Upper = String.prototype.first2Upper || function(){
 return this.charAt(0).toUpperCase()+this.slice(1);
}
//usage
'somestring'.first2Upper(); //=> Somestring

And for your array using map in combination with this extension would be:

var numArray = ["one", "two", "three", "four"]
               .map(function(elem){return elem.first2Upper();});
// numArray now: ["One", "Two", "Three", "Four"]

See MDN for explanation of and shim for the map method

score 2 · Accepted Answer · answered Aug 31 '13 at 09:53

You are almost there. Instead of uppercasing the entire string, uppercase only the first character.

Array.prototype.myUcase = function()
{
    for (var i = 0, len = this.length; i < len; i += 1)
    {
          this[i] = this[i][0].toUpperCase() + this[i].slice(1);
    }
    return this;
}

var A = ["one", "two", "three", "four"]
console.log(A.myUcase())

Output

[ 'One', 'Two', 'Three', 'Four' ]

public override · Answer 4 · 2013-09-02T06:09:15.593

Array.prototype.ucfirst = function () {

    for (var len = this.length, i = 0; i < len; i++) {

        if (Object.prototype.toString.call(this[i]) === "[object String]") {
            this[i] = (function () {
                return this.replace(
                    /\b([a-z])[a-z]*/ig,
                    function (fullmatch, sub1) {
                        return sub1.toUpperCase() + fullmatch.slice(1).toLowerCase();
                    }
                );
            }).call(this[i]);
        }

    }
    return this;
};

console.log(["conVertInG", "fIRST", "ChaRcteR", "OF", new Array, String, new String("string tO UPPER CASE [duPLicatE]")].ucfirst());
//
// ["Converting", "First", "Charcter", "Of", [], String(), "String To Upper Case [Duplicate]"]
//

Converting First Charcter of String to Upper Case

4 Answers4