Jagged array

<h2 id="examples">Examples</h2>
In <a href="/facts/C_Sharp_(programming_language)/UC2gxeyb">C#</a> and <a href="/facts/Java_(programming_language)/9ScgFyAL">Java</a><a class="footnote-ref" id="fnref:5" href="#fn:5">5</a> jagged arrays can be created with the following code:<a class="footnote-ref" id="fnref:6" href="#fn:6">6</a>

int[][] c;
c = new int[2][]; // creates 2 rows
c[0] = new int[5]; // 5 columns for row 0
c[1] = new int[3]; // create 3 columns for row 1

In <a href="/facts/C_(programming_language)/Ky2No763">C</a> and <a href="/facts/C%2B%2B/Et0F2qn9">C++</a>, a jagged array can be created (on the stack) using the following code:

int jagged_row0[] = {0,1};
int jagged_row1[] = {1,2,3};
int *jagged[] = { jagged_row0, jagged_row1 };

In C/C++, jagged arrays can also be created (on the heap) with an array of pointers:

int *jagged[5];

jagged[0] = malloc(sizeof(int) * 10);
jagged[1] = malloc(sizeof(int) * 3);

In <a href="/facts/C%2B%2B/CLI/3HtoUSrY">C++/CLI</a>, jagged array can be created with the code:<a class="footnote-ref" id="fnref:7" href="#fn:7">7</a>

using namespace System;
int main()
{
 array<array<double> ^> ^ Arrayname = gcnew array <array<double> ^> (4); // array contains 4 
 //elements
 return 0;
}

In <a href="/facts/Fortran/m1KqjcMU">Fortran</a>, a jagged array can be created using derived types with allocatable component(s): 

type :: Jagged_type
 integer, allocatable :: row(:)
end type Jagged_type
type(Jagged_type) :: Jagged(3)
Jagged(1)%row = [1]
Jagged(2)%row = [1,2]
Jagged(3)%row = [1,2,3]

In <a href="/facts/Python_(programming_language)/YbuGqofa">Python</a>, jagged arrays are not native but one can use <a href="/facts/List_comprehensions/aYAax9k0">list comprehensions</a> to create a multi-dimensional list which supports any dimensional matrix:<a class="footnote-ref" id="fnref:8" href="#fn:8">8</a>

multi_list_3d = [[[] for i in range(3)] for i in range(3)]
# Produces: [[[], [], []], [[], [], []], [[], [], []]]

multi_list_5d = [[[] for i in range(5)] for i in range(5)]
# Produces: [[[], [], [], [], []], [[], [], [], [], []], [[], [], [], [], []], [[], [], [], [], []], [[], [], [], [], []]]

<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Variable-length_array/eYknlUTc">Variable-length array</a></li>
<li><a href="/facts/Iliffe_vector/uH4jDg9I">Iliffe vector</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1">King, K. N. (2008). C Programming. W. W. Norton. p. 301. ISBN 978-0-393-97950-3. <a href="978-0-393-97950-3" target="_blank">978-0-393-97950-3</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></li>
<li id="fn:2">Handbook of Data Structures and Applications. CRC Press. 2004. <a href="#fnref:2" class="footnote-back-ref">↩</a></li>
<li id="fn:3">Jesse Liberty; Brian MacDonald (18 November 2008). Learning C# 3.0. "O'Reilly Media, Inc.". pp. 210–. ISBN 978-0-596-55420-0. <a href="978-0-596-55420-0" target="_blank">978-0-596-55420-0</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></li>
<li id="fn:4">Don Box (2002). Essential .Net: The Common Language Runtime. Addison-Wesley Professional. p. 138. ISBN 978-0-201-73411-9. <a href="978-0-201-73411-9" target="_blank">978-0-201-73411-9</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></li>
<li id="fn:5">"Jagged Array in Java - GeeksforGeeks". GeeksforGeeks. 2016-02-03. Retrieved 2018-08-13. <a href="https://www.geeksforgeeks.org/jagged-array-in-java/" target="_blank">https://www.geeksforgeeks.org/jagged-array-in-java/</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></li>
<li id="fn:6">Paul J. Deitel; Harvey M. Deitel (26 September 2008). C# 2008 for Programmers. Pearson Education. p. 40. ISBN 978-0-13-701188-9. <a href="978-0-13-701188-9" target="_blank">978-0-13-701188-9</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></li>
<li id="fn:7">"Jagged Arrays". FunctionX. Retrieved 26 November 2014. <a href="http://www.functionx.com/cppcli/arrays/jagged.htm" target="_blank">http://www.functionx.com/cppcli/arrays/jagged.htm</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></li>
<li id="fn:8">"Lists in Python Demystified". Alvin.io. Retrieved 31 January 2016. <a href="http://alvin.io/lists-in-python-demystified-part-2/" target="_blank">http://alvin.io/lists-in-python-demystified-part-2/</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></li>
</ol>

Jagged array open-in-new

Jagged array