data structures in java

#string
string = 'Hi my name is Dr.Hippo'
#integer(whole number)
integer = 12345
#floating point number
fl = 123.456
#list
li = [1,2,3,,'string',None]
#boolean
t = True
f = False
#none(equivalent to null or undefined in other languages)
n = None
#dictionary
dictionary = {'key':'value'}

Data Structures
in Java: Array, Collections Framework, Map.
Depending on the data that I am working with, I use Arrays , lists,sets, maps

Array=
- It is fixed size.
- Ordered
-Allows Duplicates
-Can store Primitives and objects
-Can be multi-dimensional
-Build in data structure


List (implementing class ArrayList, Stack, LinkedList,
Vector)
List is the only Interface that has index.
- Size is dynamic.
- Ordered
- Allows Duplicates
- Can not store primitives

ArrayList (It’s array based collection. Internally uses
arrays. Dynamic array)
- Size is dynamic.
- Ordered
- Allows Duplicates
- Can not store primitives
- Implementing class of List interface in Collection
framework

  
  LinkedList
- Stores data in individual nodes that are
connected to each other
- Each node will have a pointer to the next
node/value
- Implementing class of List and Deque interfaces
  
  
  Set (implementing class HashSet, LinkedHashSet)
Collection of unique/distinct values. No duplicates.
- Size is dynamic.
- Not ordered
- Unique values
When we want the Set or Map to accept only unique
objects from our custom class, we need to override
equals() and hashCode() methods inside our custom
class.

class Test { 
      
// class contents 
void show()  
{ 
    System.out.println("Test::show() called"); 
} 
} 
  
public class Main { 
      
    // Driver Code 
    public static void main(String[] args) 
    { 
          
        // all objects are dynamically  
        // allocated 
        Test t = new Test();  
        t.show(); // No error  
    } 
} 

in javascript data structures includes arrays, maps, and sets

// Stack implementation in C

#include <stdio.h>
#include <stdlib.h>

#define MAX 10

int count = 0;

// Creating a stack
struct stack {
  int items[MAX];
  int top;
};
typedef struct stack st;

void createEmptyStack(st *s) {
  s->top = -1;
}

// Check if the stack is full
int isfull(st *s) {
  if (s->top == MAX - 1)
    return 1;
  else
    return 0;
}

// Check if the stack is empty
int isempty(st *s) {
  if (s->top == -1)
    return 1;
  else
    return 0;
}

// Add elements into stack
void push(st *s, int newitem) {
  if (isfull(s)) {
    printf("STACK FULL");
  } else {
    s->top++;
    s->items[s->top] = newitem;
  }
  count++;
}

// Remove element from stack
void pop(st *s) {
  if (isempty(s)) {
    printf("\n STACK EMPTY \n");
  } else {
    printf("Item popped= %d", s->items[s->top]);
    s->top--;
  }
  count--;
  printf("\n");
}

// Print elements of stack
void printStack(st *s) {
  printf("Stack: ");
  for (int i = 0; i < count; i++) {
    printf("%d ", s->items[i]);
  }
  printf("\n");
}

// Driver code
int main() {
  int ch;
  st *s = (st *)malloc(sizeof(st));

  createEmptyStack(s);

  push(s, 1);
  push(s, 2);
  push(s, 3);
  push(s, 4);

  printStack(s);

  pop(s);

  printf("\nAfter popping out\n");
  printStack(s);
}