[Tutorial] Arrays

[Andy]

since arrays are essential in programming, i thought i'd make a little tutorial for the newbies

arrays are simply a collection of variables with the same type, to identify them, you'll have to call them up using their subscripts. If u were to store 10 names using variables and to not use arrays, you'll have to declare them one by one:

code:

var names1, names2, names3, names4, names5, names6, names7, names8, names9, names10 :string

this may not seem too hard, but what if u were to store 100 names instead? (if u were thinking of putting them in one string and indexing it then shut up, and keep it to ur self smart @SS)

code:

var names1, names2, names3, names4, names5, names6, names7, names8, names9, names10 ... names100 :string

as you can see, this gets very long and boring after a while, so the smart ppl who invented programming languages came up with an idea : allow the user to store data of the same type under one variable: the arrays.
here is the code for creating that 100 names of variable with an array.

code:

var names: array 1..100 of string

where names is the array name, 1 is the starting of the array, 100 is the end of the array, and string is the type of the array. All the variables decalred in an array have to be the same type, whether it is integer, real, string, or boolean (if you know types then shut up smart @SS)

to call up a stored value in the array, you must type the array named, and then the subscript (variable # in the array) in barrackets. to call up the 49th string in the predefined array

code:

names (49)

arrays, however, cannot be declared like normal variables, to declare an array one must use init

code:

var names: array 1..10 of string:=init("a", "b", "c", "d", "e", "f", "g", "h", "i", "j",)

you cannot skip one variable and go on to the other, this is why init is only used when declaring an array with a few subscripts to declare large number of variables in an array, you can use a for loop

code:

for i:1..100 names(i):="" end for

the previous code initializes the variables in the array to be nothing. The upper command tells you the higher boundry of an array and the lower command tells you the lower bondry of an array

code:

var names: array 50..100 of string upper(names)=100 lower(names)=50

Arrays can be multidimentioned, you can have 2D arrays, 3D, arrays 4D arrays, 100D arrays. each dimention allows the user to multiply the original array by the number of sectors on the next dimention(that didn't make much sense). In short, multidementional arrays are just arrays of arrays. here is an example

code:

var grid:array 1..10,1..10 of int

this declares grid as a two dimentional array allowing it to store 100 variables. there are 10 sectors in every one of the first set of range

you can also change the upper boundry of the array, but not the lower ones, you have to declare them as flexible arrays

code:

var name : flexible array 1..10 of string

this tells the computer that the array is flexible. to change the the upper boundry of the array you have to use the 'new' command, the following code chages the upper of the array to 100

code:

new name , 100

to sort an list of arrays, you simply compare each one with another

code:

for i:1..upper(names)-1 for j:i+1,upper(names) if names(j)<names(i) then temp:=names(j) names(j):=names(i) names(i):=temp end if end for end for

this code sorts the names array in alphabetical order

well this is about it, if you read all of this, you should be pretty familiar with arrays. if you have any troubles, just pm me 8)

[Andy]

dammit, tony made a tutorial on arrays too, but anyways, my is longer, better, and easier to understand rite guys? hey wait a second, how come there are no replies in this post, damn you @SS sucking ppl,
AHHHH i'm just kidding, no Asok you psycho, leave me alone
*bamm*
*fomp*

[Kingnoz]

here u go, i will give u a post

[Andy]

thanx

[JSBN]

nice job, +10 bits

[Andy]

hey tony, you should make my arrays tutorial as a sticky instead of yours, mine's much better, rite?

[vexd]

hey thanks for the info

[Andy]

yes! my post is back up top! lol

[Thuged_Out_G]

maybe you should consider adding how to delete elements of an array...im a decent turing programmer...and i cant figure out how to do it ...lol

[Andy]

just move every element up after the one u want to delete, and use the flexible arraything... i'm pretty sure you can shorten the length of the arry

[netninja]

REWRITE OF WHOLE QUESTION:

I would like to make a var that has more than one value, for eg. var blah, and an array, with numbers 1..10 for eg. and each of those 10 vars has a value of 10,30,40,50 for eg. and also the value of lucy, betty, alicia... etc

How would i go about doing that??

[Andy]

then u gotta read up on my records tutorial... found here http://www.compsci.ca/v2/viewtopic.php?t=2325

[Thuged_Out_G]

how do you change the upper bounds of a 2d array?

[zylum]

you can't:

Quote:

In the current implementation (1999), with a multi-dimensional array with a non-zero number of total elements, it is a run-time error to change any but the first dimension (unless one of the new upper bounds is one less than the corresponding lower bound, giving 0 elements in the array) as the algorithm to rearrange the element memory locations has not yet been implemented.

[AsianSensation]

Thuged_Out_G wrote:

how do you change the upper bounds of a 2d array?

with multidimensional dynamic arrays you could, you can't change the lower bound though.

multidimensional flexible array works in 4.0.5