2-Dimensional Arrays

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2-Dimensional Arrays
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One-Dimensional Array

• The array elements are selected using a one index

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Two-Dimensional Array

• A two-dimensional array has two indices.

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Defining a 2-Dimensional Array
1. Define an array object reference variable 
double a 2. Create the
array and store the location of the first element
of the array in the (array) object reference
variable a new double34
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Defining an initialized 2-dim. array
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Accessing elements of a 2-dimensional array
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Traversing (visiting) all elements in a
2-dimensional array

• We can use the following nest for-loop to visit
  all elements

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Using 2-dimensional arrays --- manipulating
pictures

• This coordinate system is the same one used for
  the Canvas 
• program

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Manipulating Pictures (1)

• The picture consists of many number of (rows of)
  dots
• A dot is called a pixel.
• Each pixel has a color...