How to: Initialize a Jagged Array
When you initialize a jagged array variable, you can specify the dimension lengths only for the top-level array. There are several ways you can do this:
To initialize a jagged array variable
In the array variable declaration, specify the top-level index upper bound inside the first pair of parentheses, separated by commas. The following example declares and creates a variable to hold a jagged array of Byte elements, specifying only the top-level upper bound.
Dim rainfall(11)() As ByteFollowing the execution of this statement, the array in variable rainfall holds 12 elements, each of which is an empty array of Byte elements.
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In the New clause, specify the top-level index upper bound inside the first pair of parentheses, and supply empty braces ({}). The following example declares and creates a variable to hold a jagged array of Short elements, specifying only the top-level upper bound.
Dim snowfall()() As Short = New Short(11)() {}Following the execution of this statement, the array in variable snowfall holds 12 elements, each of which is an empty array of Short elements.
Note
You can initialize the top-level index upper bound in only one place. If you specify an upper bound in the parentheses following the array variable name, you cannot use a New clause. If you specify the upper bound in the parentheses in the New clause, you must leave the parentheses following the variable name empty.
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In the New clause, specify the top-level index upper bound inside the parentheses, and supply the element values inside the braces ({}). The following example declares, creates, and initializes a variable to hold a jagged array of Char elements, specifying the top-level upper bound and the values. Note the nested New clauses to initialize the bottom-level arrays.
Dim decodeValues()() As Char = New Char(1)() {New Char() {"a"c, "b"c}, New Char() {"p"c, "q"c}}Following the execution of this statement, the array in variable decodeValues holds two elements, each of which is a Char array of length 1 with the element at index 0 holding an initialized value. If you supply both the top-level upper bound and the values, you must include a value for every top-level element from index 0 through the upper bound.
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In the New clause, omit the top-level parentheses and supply the element values inside the braces ({}). The following example declares, creates, and initializes a variable to hold a jagged array of Byte elements, specifying only the element values. Note the two levels of braces in the New clause.
Dim firstValues()() As Byte = {New Byte() {2, 1}, New Byte() {3, 0}}Following the execution of this statement, the array in variable firstValues has length 2, with elements firstValues(0) and firstValues(1). Each of the elements is initialized to a two-element Byte array, the first with element values 2 and 1 and the second with element values 3 and 0.
See Also
Tasks
How to: Declare an Array Variable
How to: Create an Array of Arrays
How to: Initialize an Array Variable
How to: Initialize a Multidimensional Array