Question

In most languages, can the size of an array be changed while the program is running?

Short answer

Explain your answer. Answer: No, in most programming languages like C and C++, the size of an array is fixed and cannot be changed during runtime without reallocating memory. However, there are alternative data structures and approaches that allow resizing arrays during execution, such as dynamic arrays, vectors in C++, and lists in Python.

Step-by-step solution

Understand arrays

An array is a data structure that can store a fixed-size collection of elements, all of the same type. Typically, memory is allocated for arrays in a contiguous block. This means that the elements of the array are stored together, with no gaps in between.

Fixed vs Dynamic arrays

There are two types of arrays: fixed-size arrays and dynamic arrays. Fixed-size arrays have a pre-determined size and cannot be changed during the execution of the program, while dynamic arrays can resize themselves during runtime.

Programming languages and array resizing

The ability to resize an array depends on the programming languages. In most programming languages like C and C++, the size of an array is fixed and cannot be changed during runtime without reallocating memory. However, languages like Python, Java, and JavaScript have the flexibility to change the array's size during runtime by using built-in functions or libraries.

Array resizing in C++

In C++, if you want to resize an array during runtime, you can make use of the STL (Standard Template Library) vector. A vector is a dynamic array, which can grow and shrink during runtime as needed. You can use the `push_back` and `pop_back` functions to add and remove elements at the end of the vector, thus effectively resizing it.

Use of dynamic arrays in Python

In Python, a built-in data structure called a `list` is used to represent an array. Lists are dynamically sized by default, so you can add or remove elements during runtime using methods like `append` and `pop`.

Conclusion

In conclusion, while the size of arrays cannot be changed directly during runtime in many programming languages, there are alternative data structures and approaches that allow resizing arrays during execution. This includes using dynamic arrays or built-in language-specific structures like vectors in C++ and lists in Python.