Array Introduction in X++ Language

 

There are three kinds of arrays:

• Dynamic

• Fixed-length

• Partly on disk

Code

static void RummanJob1(Args _args)
{

    // array declaration example
    // by Rumman Ansari

        // A dynamic array of integers
        int arrayName[]; 
     
        // A fixed-length real array with 100 elements
        real arrayName1[100]; 
     
        // A dynamic array of dates with only 10 elements in memory
        date arrayName2[,10]; 
     
        // A fixed length array of NoYes variables with
        // 100 elements and 10 in memory
        NoYes arrayName3[100,10];
        
        print "Done.";
        pause;

}

Array Indices

Array indexes begin at 1. The first item in the array is called [1], the second [2], and so on.

The syntax for accessing an array element is:

ArrayItemReference = ArrayVar [ Index ]

where ArrayVar is the identifier of the array, and Index is the number of the array element. Index can be an integer expression.

For example, a[7] accesses item number 7 in array a.

In X++, item zero[0] is used to clear the array! Assigning a value to index 0 in an array resets all elements in the array to the default value. For example,

intArray[0] = 0; //Resets all elements in intArray

Dynamic Arrays

A dynamic array is declared with an empty array option (that is, only square brackets):

//Dynamic array of integers
int intArrayName[];

// Dynamic array of variables of type Datatype

Datatype arrayVariableName[];

Fixed-length Arrays

A fixed-length array can hold the number of items that is specified in the declaration. Fixed-length arrays are declared like dynamic arrays but with a length option in the square brackets:

boolean boolArray[100]; //Fixed-length array of booleans with 100 items

Partly On Disk Arrays

Partly on disk arrays are declared either as dynamic or fixed-length arrays with an extra option that declares how many items should be held in memory. The other items are stored on disk and automatically loaded when referenced.

//Dynamic integer array with only 100 elements in memory.
int arrayVariableName [ ,100]; 
 
//Fixed-length string array with 800 elements, and only 100in memory.
str arrayVariableName [800, 100]