Arrays

• An array is a data structure that holds several data items or elements of the same data type.
• When you want to store many related pieces of data with the same data type, it is often better to use an array instead of many separate variables.
• An array can be declared using a single identifier and can be processed efficiently using iteration techniques.
• Each position in an array is identified by an index. Most languages use zero-based indexing which means that the indexing starts at 0.
• You will find that different programming languages implement arrays in various ways. In some languages, an array is implemented as a static data structure. Its length is fixed when declared and cannot be changed during runtime.
• In Python, a list is a data structure that can be indexed like an array. However, it is dynamic and can hold different types of data (at the same time) so does not conform to the pure definition of an array.
• You can think of a one-dimensional array as a single row of values.
• Arrays can have more than one dimension. You could envisage a two-dimensional array as a table with rows and columns. A two-dimensional array is also called a matrix.