Month: September 2013

Link for calling convention

http://www.codeproject.com/Articles/1388/Calling-Conventions-Demystified

http://visual.merriam-webster.com/energy/geothermal-fossil-energy/oil/offshore-prospecting.php

offshore prospecting

Vibrations from an exploding charge in the sea are used to locate oil deposits; prospecting offshore is more difficult than on land.

petroleum trap

Assemblage of porous rocks that contain recoverable oil reserves, which are produced from marine or land deposits.

blasting charge

Quantity of explosives (substances capable of discharging high-temperature gases over a very short time period) that produce shock waves when detonated.

seismographic recording

A recording made using an apparatus called a seismograph; the analysis of its shock wave echoes detects the presence of rock layers that might contain pockets of petroleum or gas.

shock wave

The shock wave spreads and sends back an echo, which varies with the density and depth of the layers of subsoil; with this information, the composition of the subsoil can be determined.

wave

Responses HTTP

If status code begin with

2: Basic mean OK

3: basic ok but need to do difference technique to find document

4: Error on browser side (eg: find document doesn’t exist)

5: Error on Server side (eg: server broke )

GET method

Tower

http://en.wikipedia.org/wiki/Tower_of_Hanoi#Recursive_solution


 var a={
    a: [1,2,3,4,5],
    name: "a"}
var b={
a: [],
name : "b"
};
var c={
a:[],
name : "c"
};

var cnt=0;
 
 
function hn(n,from,to,im){
    if (n===1){
        console.log(from.a[from.a.length-1]+" from "+from.name + " to "+to.name)
        to.a.push(from.a.pop());
        ++cnt;
    }else{
        hn(n-1,from,im,to);
        console.log(from.a[from.a.length-1]+" from "+from.name + " to "+to.name)
        to.a.push(from.a.pop());
        ++cnt;
        hn(n-1,im,to,from);
    }
    return to.name + ": " + to.a+" total " +cnt + " times"
}
 
hn(a.a.length,a,b,c);

move n−1 discs from A to B. This leaves disc n alone on peg A
move disc n from A to C
move n−1 discs from B to C so they sit on disc n

Prototype (JC)

http://sporto.github.io/blog/2013/02/22/a-plain-english-guide-to-javascript-prototypes/

The ‘prototype’ property points to the object that will be asigned as the prototype of instances created with that function when using ’new’. Confusing? This is easier to explain with an example:

Deactive user in Linux

jsmith:x:1001:1000:Joe Smith,Room 1007,(234)555-8910,(234)555-0044,email:/home/jsmith:/bin/sh

The fields, in order from left to right, are:[2]

The first field is the user name, i.e. the string a user would type in when logging into the operating system: the logname. Each record in the file must have a unique user name field.
The second field stores information used to validate a user’s password; however in most modern uses this field is usually set to “x” (or some other indicator) with the actual password information being stored in a separate shadow password file. Setting this field to an asterisk “*” is the typical way to deactivate an account to prevent it being used.
The third field is the user identifier, the number that the operating system uses for internal purposes. It does not have to be unique.
The fourth field is the group identifier. This number identifies the primary group of the user; all files that are created by this user may initially be accessible to this group.
The fifth field, called the Gecos field, is commentary that describes the person or account. Typically, this is a set of comma-separated values including the user’s full name and contact details.
The sixth field is the path to the user’s home directory.
The seventh field is the program that is started every time the user logs into the system. For an interactive user, this is usually one of the system’s command line interpreters (shells).

Cash Register (JC codeacademy)

function StaffMember(name,discountPercent){
    this.name = name;
    this.discountPercent = discountPercent;
}

var sally = new StaffMember("Sally",5);
var bob = new StaffMember("Bob",10);

// Create yourself again as 'me' with a staff discount of 20%
var me=new StaffMember("me",20);

var cashRegister = {
    total:0,
    lastTransactionAmount: 0,
    add: function(itemCost){
        this.total += (itemCost || 0);
        this.lastTransactionAmount = itemCost;
    },
    scan: function(item,quantity){
        switch (item){
        case "eggs": this.add(0.98 * quantity); break;
        case "milk": this.add(1.23 * quantity); break;
        case "magazine": this.add(4.99 * quantity); break;
        case "chocolate": this.add(0.45 * quantity); break;
        }
        return true;
    },
    voidLastTransaction : function(){
        this.total -= this.lastTransactionAmount;
        this.lastTransactionAmount = 0;
    },
    // Create a new method applyStaffDiscount here
    applyStaffDiscount : function(employee){
        this.total=this.total-this.total*employee.discountPercent/100;
    }
    
};

cashRegister.scan('eggs',1);
cashRegister.scan('milk',1);
cashRegister.scan('magazine',3);
// Apply your staff discount by passing the 'me' object 
// to applyStaffDiscount
cashRegister.applyStaffDiscount(me),

// Show the total bill
console.log('Your bill is '+cashRegister.total);

Inheritance

// original classes
function Animal(name, numLegs) {
    this.name = name;
    this.numLegs = numLegs;
    this.isAlive = true;
}
function Penguin(name) {
    this.name = name;
    this.numLegs = 2;
}
function Emperor(name) {
    this.name = name;
    this.saying = "Waddle waddle";
}

// set up the prototype chain
Penguin.prototype = new Animal();
Emperor.prototype = new Penguin();

var myEmperor = new Emperor("Jules");

console.log( myEmperor.saying ); // should print "Waddle waddle"
console.log(  myEmperor.numLegs); // should print 2
console.log(  myEmperor.isAlive); // should print true

d5levelfc

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