document.write("Hello<br />");
// concat string
var s1 = "One";
var s2 = "Two";
var concat = s1 + ", " + s2;
// string length
concat.length
// substring - zero-indexed
concat.substring(6, 3);
// last char
concat.charAt(concat.length-1);
// first occurrence of w
concat.indexOf('w')
// implicit conversion
var a1 = "2";
var a2 = 4;
var total = a1 + a2; // both treated as strings
total = a1 * a2; // both treated as numbers
var total = Number(a1) + a2; // force string to number
var total = String(a2) + String(a2); // force number to string
