Javascript Note from Book: javascript: the good parts

1. single number type, internally it's 64-bits floating point. (no separate integer type!)
2. all characters  are 16 bits wide.  "A" === "\u0041"
3. Variable is FUNCTION scope, instead of BLOCK scope.  Use "var" to define a variable in a function, better at the top of function. Otherwise, the variable's scope will be global.
4. The default value can be filled with default: var myVal = Data["src"] || "no-data" ; 
5. Objects are passed by reference. They are never copied.
6. If the object lacks the property name, then JS attempts to get it from the prototype object. ==> hasOwnProperty()
7. Removing a property from one object by using "delete" may allow a property from the prototype to shine through
8. if ( typeof   myVal !== 'function' ) ...

Function

1. Function object are linked to Function.prototype and can have methods.
2. Functions can be defined inside of other functions.
3. Closure:  the function object created by a function literal contains a link to that outer context.
4. function foo( argA, argB, argC){...}       foo("one", "two");  ==>  argC will be undefined
5. Be careful about the "this" variable.
6. Function always returns a value, or undefined is returned instead.
7. Closure usage !!!
8. If methods return this, cascade calls can be enabled.   getElement("id").moveUp().color('red').tip('abc');
9. ...

TBC.....