SOURCE

function writeDocument(variable) {
  document.write(variable + "<br/>");
}
var welcomeString= "welcome";

writeDocument(welcomeString);
writeDocument(welcomeString.length);
writeDocument(" //case -------");
writeDocument(welcomeString.toLowerCase());
writeDocument(welcomeString.toUpperCase());
writeDocument(welcomeString.charAt(2));
writeDocument(welcomeString.charAt(6));
writeDocument("//-------------------------------------");
writeDocument(welcomeString.substring(3));
writeDocument(welcomeString.substring(0, 2));
writeDocument(" //replace------")
var sentence = "We have fun in our class. Do you have fun in your class?"
writeDocument(sentence);
writeDocument(sentence.replace("class","programming class"));
writeDocument(sentence.replace(/class/g,"programming class"));
writeDocument("//split-------------------------------------");
var splitSentence = "We have fun in our class";
writeDocument(splitSentence);
writeDocument(splitSentence .split(" "));
writeDocument (welcomeString);
writeDocument (welcomeString. split(""));
writeDocument(sentence.split(""));
writeDocument("//split-------------------------------------");
writeDocument(sentence.indexOf("class"));
writeDocument(sentence.lastIndexOf("class"));
writeDocument(sentence.match("class"));
writeDocument(sentence.match(/class/g));
writeDocument(sentence.search(/class/g));
writeDocument("//split-------------------------------------");

function countChar(char)
{
    var count=0;
    var str="Can you can a can as a Canner can can a can";
    var o;
    str=(str.toLowerCase())
    for(var i=0;i<str.length,i++)
    {
        var char=str.charAt(i)
    }

}