PPT: Arrays | Programming and Data Structures - Computer Science Engineering (CSE) PDF Download

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Introduction to Arrays
An array is a collection of items stored at contiguous memory locations. This design makes it easier to calculate the position of each element by simply 
adding an offset to a base value, which is the memory location of the first element (index 0).
Contiguous Storage
Elements stored in adjacent memory locations
Index Calculation
Position = Base Address + (Index × Data Type 
Size)
Staircase Analogy
Like friends standing on different steps of a 
staircase
Think of an array as a staircase where each step holds a value. You can identify any element by knowing which step (index) it occupies. The location of the 
next index depends on the data type used.
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A r r a y s
Introduction to Arrays
An array is a collection of items stored at contiguous memory locations. This design makes it easier to calculate the position of each element by simply 
adding an offset to a base value, which is the memory location of the first element (index 0).
Contiguous Storage
Elements stored in adjacent memory locations
Index Calculation
Position = Base Address + (Index × Data Type 
Size)
Staircase Analogy
Like friends standing on different steps of a 
staircase
Think of an array as a staircase where each step holds a value. You can identify any element by knowing which step (index) it occupies. The location of the 
next index depends on the data type used.
Array's Size and Indexing
In C language, arrays have a fixed size that cannot be changed after declaration. You can 
neither shrink nor expand them because memory is allocated statically by the compiler.
Zero-based Indexing
The first element of the array is indexed by a subscript of 0
One-based Indexing
The first element of the array is indexed by a subscript of 1
N-based Indexing
Base index can be freely chosen, may allow negative values or other scalar data 
types
Different programming languages implement different indexing systems, though zero-
based indexing is the most common in modern languages like C, C++, Java, and Python.
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A r r a y s
Introduction to Arrays
An array is a collection of items stored at contiguous memory locations. This design makes it easier to calculate the position of each element by simply 
adding an offset to a base value, which is the memory location of the first element (index 0).
Contiguous Storage
Elements stored in adjacent memory locations
Index Calculation
Position = Base Address + (Index × Data Type 
Size)
Staircase Analogy
Like friends standing on different steps of a 
staircase
Think of an array as a staircase where each step holds a value. You can identify any element by knowing which step (index) it occupies. The location of the 
next index depends on the data type used.
Array's Size and Indexing
In C language, arrays have a fixed size that cannot be changed after declaration. You can 
neither shrink nor expand them because memory is allocated statically by the compiler.
Zero-based Indexing
The first element of the array is indexed by a subscript of 0
One-based Indexing
The first element of the array is indexed by a subscript of 1
N-based Indexing
Base index can be freely chosen, may allow negative values or other scalar data 
types
Different programming languages implement different indexing systems, though zero-
based indexing is the most common in modern languages like C, C++, Java, and Python.
Array Implementation in C and C++
C++ Implementation
Arrays in C++ can be declared and initialized in a single statement. The 
example shows an integer array with 5 elements, where the first element 
is assigned the value 5.
C++ offers additional features like STL vectors that overcome some 
limitations of traditional arrays.
C Implementation
In C, arrays follow similar syntax but with more rigid memory 
management. The output shows 5 because the first element (at index 0) 
was assigned the value 5.
C requires manual memory management and doesn't provide built-in 
bounds checking, making it more prone to errors like buffer overflows.
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A r r a y s
Introduction to Arrays
An array is a collection of items stored at contiguous memory locations. This design makes it easier to calculate the position of each element by simply 
adding an offset to a base value, which is the memory location of the first element (index 0).
Contiguous Storage
Elements stored in adjacent memory locations
Index Calculation
Position = Base Address + (Index × Data Type 
Size)
Staircase Analogy
Like friends standing on different steps of a 
staircase
Think of an array as a staircase where each step holds a value. You can identify any element by knowing which step (index) it occupies. The location of the 
next index depends on the data type used.
Array's Size and Indexing
In C language, arrays have a fixed size that cannot be changed after declaration. You can 
neither shrink nor expand them because memory is allocated statically by the compiler.
Zero-based Indexing
The first element of the array is indexed by a subscript of 0
One-based Indexing
The first element of the array is indexed by a subscript of 1
N-based Indexing
Base index can be freely chosen, may allow negative values or other scalar data 
types
Different programming languages implement different indexing systems, though zero-
based indexing is the most common in modern languages like C, C++, Java, and Python.
Array Implementation in C and C++
C++ Implementation
Arrays in C++ can be declared and initialized in a single statement. The 
example shows an integer array with 5 elements, where the first element 
is assigned the value 5.
C++ offers additional features like STL vectors that overcome some 
limitations of traditional arrays.
C Implementation
In C, arrays follow similar syntax but with more rigid memory 
management. The output shows 5 because the first element (at index 0) 
was assigned the value 5.
C requires manual memory management and doesn't provide built-in 
bounds checking, making it more prone to errors like buffer overflows.
Advantages and 
Disadvantages of Arrays
Advantages
Random access to elements (O(1) time 
complexity)
Better cache locality improving 
performance
Represent multiple data items of 
same type with single name
Disadvantages
Fixed size - cannot be changed after 
declaration
Difficult insertion and deletion 
operations
Costly shifting operations for 
maintaining order
Implementation Flaws
Memory waste in data structures like stacks
No built-in bounds checking in some languages
Potential for memory leaks with objects
These characteristics make arrays suitable for some applications but problematic for others. 
When implementing more complex data structures using arrays, developers must be aware of 
these limitations.