8. Arrays in awk

An array is a table of values called elements. The elements of an array are distinguished by their indices. Indices may be either numbers or strings.

This chapter describes how arrays work in awk, how to use array elements, how to scan through every element in an array, and how to remove array elements. It also describes how awk simulates multidimensional arrays, as well as some of the less obvious points about array usage. The chapter finishes with a discussion of gawk's facility for sorting an array based on its indices.

awk maintains a single set of names that may be used for naming variables, arrays, and functions (see section User-Defined Functions). Thus, you cannot have a variable and an array with the same name in the same awk program.

8.1 Introduction to Arrays
8.2 Referring to an Array Element		How to examine one element of an array.
8.3 Assigning Array Elements		How to change an element of an array.
8.4 Basic Array Example		Basic Example of an Array
8.5 Scanning All Elements of an Array		A variation of the for statement. It loops through the indices of an array's existing elements.
8.6 The delete Statement		The delete statement removes an element from an array.
8.7 Using Numbers to Subscript Arrays		How to use numbers as subscripts in

                                awk.

8.8 Using Uninitialized Variables as Subscripts		Using Uninitialized variables as subscripts.
8.9 Multidimensional Arrays		Emulating multidimensional arrays in

                                awk.

8.10 Scanning Multidimensional Arrays		Scanning multidimensional arrays.
8.11 Sorting Array Values and Indices with gawk		Sorting array values and indices.