jquery fundamental notes

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'