SOURCE

var welcomestring = "welcome";

writeDocument(welcomestring+"<br/>"+length+"<br/>");

writeDocument(welcomestring.toLocaleLowerCase()+"<br/>");
writeDocument(welcomestring.toLocaleUpperCase()+"<br/>");

writeDocument("case1---------------------------------------------------------");

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

writeDocument(welcomestring)
writeDocument(welcomestring.length)

document.write("case2---------------------------------------------------------");

writeDocument(welcomestring.toLocaleLowerCase())
writeDocument(welcomestring.toLocaleUpperCase())

writeDocument("charAt---------------------------------------------------------");

writeDocument(welcomestring.charAt(2))
writeDocument(welcomestring.charAt(6))

writeDocument("substring---------------------------------------------------------");


writeDocument(welcomestring.substring(3))
writeDocument(welcomestring.substring(0,2))

writeDocument("replace---------------------------------------------------------");


var sentence="We class have nice tomorrow class"
writeDocument(sentence);
writeDocument(sentence.replace("class","programming"));
writeDocument(sentence.replace(/class/g,"programming"));

writeDocument("split---------------------------------------------------------");
var splitSentence="we havek sjalkj 1ssakljl1"
writeDocument(splitSentence);
writeDocument(splitSentence.split("  "));
writeDocument(welcomestring)
writeDocument(splitSentence.split("  "));
writeDocument(splitSentence.split(""));

writeDocument("IndexOf---------------------------------------------------------");
writeDocument(sentence.indexOf("class"));
writeDocument(sentence.lastIndexOf("class"));
writeDocument(sentence.match("class"));
writeDocument(sentence.match(/class/g));
writeDocument(sentence.search(/class/g));

writeDocument("---------------------------------------------------------");
var str="Can you can a can as a Canner can can a can"

function countChar(stringValue, char){
    var charcount=0
    for(var i=0; i< stringValue.length;i++)
    {
        if(stringValue.charAt(i).toLocaleLowerCase()==char)
        {
            charcount++;
        }
    }
    return charcount;
} 
writeDocument("There are "+countChar(str, "c")+" in sentence")