http://jqfundamentals.com/book/book.html#N2004B
Example 2.9. Forcing a string to act as a number
var foo = 1; var bar = '2'; // coerce the string to a number console.log(foo + Number(bar));
Example 2.10. Forcing a string to act as a number (using the unary-plus operator)
console.log(foo + +bar);
Example 2.12. Comparison operators
var foo = 1;
var bar = 0;
var baz = '1';
var bim = 2;
foo == baz; // returns true; careful!
foo === parseInt(baz); // returns true
Example 2.14. Values that evaluate to true
'0'; 'any string'; []; // an empty array {}; // an empty object 1; // any non-zero number
Example 2.15. Values that evaluate to false
0; ''; // an empty string NaN; // JavaScript's "not-a-number" variable null; undefined; // be careful -- undefined can be redefined!
Example 2.31. Creating an "object literal"
var myObject = { sayHello : function() { console.log('hello'); }, myName : 'Rebecca' }; myObject.sayHello(); // logs 'hello' console.log(myObject.myName); // logs 'Rebecca'