Types of Allocation

Introduction

In C++, we can allocate memory in two ways:

• Static allocation
• Dynamic allocation

Static allocation

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In static allocation, a fixed amount of memory is allocated to the variables or arrays before the execution of the program (during compile-time), and we cannot request more memory while the program runs.

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In static allocation:

• We must know the size of an array or variable during the compile time.
• Memory is allocated and deallocated to the variables by the compiler.

Dynamic allocation

Sometimes you will encounter a situation where you don’t know in advance how much memory is needed to store the data. Thus, dynamic allocation is needed.

Example program

Suppose you want to input a sentence from a user, but you don’t know the exact characters needed in an array.