Introduction to JavaScript

METHODS OF RUNNING JAVASCRIPT

• Using consoles on webpages
• using node.js

VARIABLES AND CONSTANTS

There are two methods of getting variables, both of which have similar syntax.

the two methods are:

• let
• var (an older version)

 In order to declare constants(i.e., variables which cannot be changed), you make use of the 'const' function.

CONSOLE.LOG

'console.log()' is used to display(print) information onto the user interface.

DATA TYPES

A list of all the data types in JavaScript are:

• strings
• number(integers and floats)
• big int: larger numbers
• Boolean: true or false
• undefined: a variable with unassigned data
• null: an empty variable, not the same as undefined
• symbol
• object: a collection of information similar to dictionaries or sets.

JAVASCRIPT OPERATORS

• ASSIGNMENT OPERATORS
• 
  
  
  
  
• ARITHMETIC OPERATORS
• 
  
  
  
  
• COMPARISON OPERATORS
• 
  
  
  
  
• LOGICAL OPERATORS
• 
  
  
  
  
• BITWISE OPERATORS

JAVASCRIPT COMMENTS

There are two main types of comments in JavaScript

check data type for all elements in a list

For more codes click here 

#check data type for all elements in a list

a = [1,"pease", 4, "dog"]

for i in a:

    if isinstance(i, int):

        print(f"{i} is an integer")

    elif isinstance(i, str):

        print(f"{i} is a string")

    else:

        pass

Simple calculator using python and tkinter

 from re import sub

from tkinter import *

#creating a window

root =  Tk()

#decale the default variable

calc = ""

#definig the function

def addi():

    global calc

    calc += "+"

    pop['text'] = calc

def subi():

    global calc

    calc += "-"

    pop['text'] = calc

def divi():

    global calc

    calc += "/"

    pop['text'] = calc

def multipl():

    global calc

    calc += "*"

    pop['text'] = calc

def ze():

    global calc

    calc += "0"

    pop['text'] = calc

def on():

    global calc

    calc += "1"

    pop['text'] = calc

def tw():

    global calc

    calc += "2"

    pop['text'] = calc

def th():

    global calc

    calc += "3"

    pop['text'] = calc

def fo():

    global calc

    calc += "4"

    pop['text'] = calc

def fi():

    global calc

    calc += "5"

    pop['text'] = calc

def si():

    global calc

    calc += "6"

    pop['text'] = calc

def se():

    global calc

    calc += "7"

    pop['text'] = calc

def ei():

    global calc

    calc += "8"

    pop['text'] = calc

def ni():

    global calc

    calc += "9"

    pop['text'] = calc

def decii():

    global calc

    calc += "."

    pop["text"] = calc

def evali():

    global calc

    try:

        calc = eval(calc)

        pop["text"] = calc

        calc = ""

    except:

        pop['text'] = "AN ERROR OCCURRED"

        calc = ""

def cleari():

    global calc

    calc = ""

    pop["text"] = calc

#naming the window

root.title("A SIMPLE CALCULATOR")

#label and entry field

m = Label(root, text="CALCULATOR", font=(25))

pop = Label(root, text='', font=(50))

#operators box

adding = Button(root, text="+",height=2, width=5, command=addi)

subtracting = Button(root, text="-",height=2, width=5, command=subi)

dividing = Button(root, text="/",height=2, width=5, command=divi)

multiplying = Button(root, text="*",height=2, width=5, command=multipl)

equating = Button(root, text="=", height=10, width=13, command=evali)

#numbers

nine = Button(root, text="9", height=2, width=5, command=ni)

eight = Button(root, text="8", height=2, width=5, command=ei)

seven = Button(root, text="7", height=2, width=5, command=se)

six = Button(root, text="6", height=2, width=5, command=si)

five = Button(root, text="5", height=2, width=5, command=fi)

four = Button(root, text="4", height=2, width=5, command=fo)

three = Button(root, text="3", height=2, width=5, command=th)

two = Button(root, text="2", height=2, width=5, command=tw)

one = Button(root, text="1", height=2, width=5, command=on)

zero = Button(root, text="0", height=2, width=5, command=ze)

ccc = Button(root, text="C", height=2, width=5, command=cleari)

deci = Button(root, text=".", height=2, width=5, command=decii)

#placing on screen

m.place(x=190, y=0)

pop.place(x=100, y=30)

#placiing operators

adding.place(x=100, y=60)

subtracting.place(x=150, y=60)

dividing.place(x=200, y=60)

multiplying.place(x=250, y=60)

equating.place(x=300, y=60)

#placing digits

nine.place(x=100, y=100)

eight.place(x=150, y=100)

seven.place(x=200, y=100)

six.place(x=250, y=100)

five.place(x=100, y=140)

four.place(x=150, y=140)

three.place(x=200, y=140)

two.place(x=250, y=140)

ccc.place(x=100, y=180)

one.place(x=150, y=180)

zero.place(x=200, y=180)

deci.place(x=250, y=180)

root.resizable(False, False)

root.geometry("500x500")

root.mainloop()

Problem 2 - The game of Nims / Stones

 In this game, two players sit in front of a pile of 100 stones. They take turns, each removing between 1 and 5 stones (assuming there are at least 5 stones left in the pile). The person who removes the last stone(s) wins.

Write a program to play this game. This may seem tricky, so break it down into parts. Like many programs, we have to use nested loops (one loop inside another).

In the outermost loop, we want to keep playing until we are out of stones.

Inside that, we want to keep alternating players. You have the option of either writing two blocks of code, or keeping a variable that tracks the current player. The second way is slightly trickier since we haven't learned lists yet, but it's definitely do-able!

Finally, we might want to have an innermost loop that checks if the user's input is valid. Is it a number? Is it a valid number (e.g. between 1 and 5)? Are there enough stones in the pile to take off this many? If any of these answers are no, we should tell the user and re-ask them the question.

So, the basic outline of the program should be something like this:

TOTAL = 100

MAX = 5

pile = TOTAL # all stones are in the pile to start

while [pile is not empty]:

while [player 1's answer is not valid]:

[ask player 1]

[check player 1's input... is it valid?]

[same as above for player 2]

Note how the important numbers 100 and 5 are stored in a single variable at the top. This is good practice -- it allows you to easily change the constants of a program. For example, for testing, you may want to start with only 15 or 20 stones.

Be careful with the validity checks. Specifically, we want to keep asking player 1 for their choice as long as their answer is not valid, BUT we want to make sure we ask them at least ONCE. So, for example, we will want to keep a variable that tracks whether their answer is valid, and set it to False initially.

When you're finished, test each other's programs by playing them!

Python as an OOPs

 For those of you who don't know, oop stands for Object-Oriented Programming. Is python an oop, and why?

Python Function

 Function is a collection of operations which can be easily accessed throughout a program. these operation accepts a variable and passes it through the stated operations to give an output.

Python Loops and Iterations

 Loops are used to iterate within a set of variables. This can either be a list, string, tuple etc.

Python Conditionals

Conditionals are used to carry out functions which are depending on set rules I e conditions. To work with conditionals, you'll need to declare the if ..... else statement.