Selected name array element selection

If the control expression is true, the result is exprl, otherwise, the result is expr2. For example, one might want to use a variable called index to select a specific element of an array named stheta. If index is 0, we want to access the zeroth element, if index is 1 or -1, we want to access the first element of the array, if it is 2 or —2, we want to access the second element, and so on. This is easily written using a conventional if statement ... 

The following illustrate how indexed names can be used to select elements of one- and two-dimensional arrays (ID and 2D). 

Sliced names allow a continuous range or slice of elements from a one-dimensional array to be selected, as the following examples show. 

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