---
# System prepended metadata

title: Python

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# Python

## Easy:
1. How will you get the length of the string?
    - `len(string)` − Returns the length of the string.
    
1. what is the difference between a list, dictionary and a tuple in python ?
	- list: 
		- mutable
		- ordered
	- tuple:
		- non-mutable
		- ordered
		- faster
	- dict:
		- ordered
		- key:value pairs

2. What is the purpose of `**` operator?
    - exponent operator

2. what are the `int` and `str` methods in Python?
	- `int()` converts string to integer
	- `str()` converts integer to string

3. is indentation optional in Python?
	- no it's required to separate blocks of code from each other


4. do we need to declare variables with data types in Python?
	- no, Python is dynamically typed

## Medium:
1. what would be the output of the following code:
```Python
    list1 = [2, 33, 222, 14, 25]
    print(list1[-2])
```
> 14

2. what are loop interruption statements in Python?
	- break: terminates entire loop
	- continue: terminates a single iteration

3. how is python an interpreted language?
	- python code gets evaluated line by line with the python interpreter unlike compiled languages that gets translated to machine code then to an executable.

3. what is a lambda in python
    - It is a single expression anonymous function often used as inline function.

## Hard:
1. explain the `with` statement in Python
	- `with` closes the file automatically as soon as the block ends unlike `file.close()` and `file.open()`

# C++
## Easy
1. what's the different between X++ and ++X
1. 
1. what's a class in C++
	- classes are user-defined data types (blueprint for objects), It reflects the different entities, attributes, and actions.

2. what's an object in C++
	- they are instances of classes

## Medium
1. Is it possible for a C++ program to be compiled without the main() function?
	- yes, it's possible however the program will stop after compilation and won't execute.

2. what will be the value of `i` and `j` after the below code is executed?
```C++
int i = 5;
int j = i++;
````
	- j = 5, i = 6

3. how is C++ different than C?
	- C is a procedural programming language
	- C++ is a procedural programming language as well as an Object Oriented Programming language

## Hard
1. why is the `volatile` keyword used?
	- The volatile keyword informs the compiler that a variable may change without the compiler knowing it. Variables that are declared as volatile will not be cached by the compiler, and will thus always be read from memory.

2. what is an Object Oriented Programming Language
	- OOP is a method of programming that involves creating objects from classes (which is the blueprint of the object)

# matlab 
## easy 
1. how to write hello world to assign text to a variable
   - enclose sequences of characters in double quotes
   - A= "hello, world" ;
   
2. how to create an array with four elements in a single row?
   - ex: 
```matlab
a = [1 2 3 4] 
a = 1×4

     1     2     3     4
```
3. how to create an array with four elements in a single cloumn ? 
   -  ex  a = [1; 2 ; 3 ; 4]
   -  a = 4×1

     1 
     2
     3
     4
4. how to create a matrix that has multiple rows ?
   -  ex a = [1 2 3; 4 5 6; 7 8 10]
   -  a = 3×3
```
     1     2     3
     4     5     6
     7     8    10
```
5. what is the function name to clear command window 
   - The clc function clears the Command Window.
6. how to create two dimensional line plot and what is the function we use?
   - x = value , y = value 
   - plot(x,y)
7. how To add plots to an existing figure?
   - use hold on 

## medium 
1. state another way to create a matrix 
   -  is to use a function as ones , zeros or rand 
   -  ex : z = zeros(5,1) z = 5×1

     0
     0
     0
     0
     0
2. how to transpose a matrix 
   - use a single quote (')
   - ex: a' ans = 3×3

     1     4     7
     2     5     8
     3     6    10
3. how to write hello world to assign text to a variable
   - enclose sequences of characters in double quotes
   - A= "hello, world" ;

## hard
1.  What are the types of loops does Matlab provides?
    - Matlab provides loops like While Loop, For Loop and Nested Loops
2. List out the operators that MatLab allows? 
   - Matlab allows following Operators like Arithmetic Operators,Relational Operators,Logical Operators, Bitwise Operations and Set Operations

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