Dela

Dela is used to delete elements from single-sized arrays, from a given index.

Syntax

  Dela START ARRAY_LIST
  Dela START, NUMBER ARRAY_LIST
  Dela START, NUMBER, LIMIT ARRAY_LIST

• START is an integer expression that gives the index in the arrays from which the deletions are made. It cannot exceed the highest index or fall short of the smallest index available in the array list.
• NUMBER is an integer expression that gives the number of indexes to be deleted. It must be strictly positive. If not given by the syntax, '1' will be used.
• LIMIT is an integer expression that gives the index in the arrays where the deletion ends. LIMIT cannot exceed the highest index and the smallest index available in the array list.
• ARRAY_LIST is a list of arrays variable (at least one), separated by commas.

Examples:

Let's imagine we have three arrays called COMPOSER(1..10), NAME(1..10), and BIRTH_YEAR(1..10) that have at the beginning the following values:

Index	NAME	FIRSTNAME	BIRTH YEAR
1	BUXTEHUDE	Dietrich	1637
2	BACH	Johann Sebastian	1685
3	MOZART	Wolfgang Amadeus	1756
4	BEETHOVEN	Ludwig	1770
5	SCHUBERT	Frantz	1797
6	WAGNER	Richard	1813
7	STRAUSS	Richard	1864
8	SCHOENBERG	Arnold	1874
9	BERG	Alban	1885
10	STOCKHAUSEN	Karlheintz	1928

After execution of:

Dela 1 COMPOSER, NAME, BIRTH_YEAR

The result will be the following. The empty lines at the end of the arrays are not listed:

Index	NAME	FIRSTNAME	BIRTH YEAR
1	BACH	Johann Sebastian	1685
2	MOZART	Wolfgang Amadeus	1756
3	BEETHOVEN	Ludwig	1770
4	SCHUBERT	Frantz	1797
5	WAGNER	Richard	1813
6	STRAUSS	Richard	1864
7	SCHOENBERG	Arnold	1874
8	BERG	Alban	1885
9	STOCKHAUSEN	Karlheintz	1928

Let's now execute the following instruction on the previous result:

Dela 2,3 COMPOSER, NAME, BIRTH_YEAR

The result will become:

Index	NAME	FIRSTNAME	BIRTH YEAR
1	BACH	Johann Sebastian	1685
2	WAGNER	Richard	1813
3	STRAUSS	Richard	1864
4	SCHOENBERG	Arnold	1874
5	BERG	Alban	1885
6	STOCKHAUSEN	Karlheintz	1928

Let's now execute the following instruction on the previous result:

Dela 3,2,5 COMPOSER, NAME, BIRTH_YEAR

The result will become:

Index	NAME	FIRSTNAME	BIRTH YEAR
1	BACH	Johann Sebastian	1685
2	WAGNER	Richard	1813
3	BERG	Alban	1885
4			0
5			0
6	STOCKHAUSEN	Karlheintz	1928

Let's now execute the following instruction on the previous result:

Dela 6,1 COMPOSER, NAME, BIRTH_YEAR

The result will become:

Index	NAME	FIRSTNAME	BIRTH YEAR
1	BACH	Johann Sebastian	1685
2	WAGNER	Richard	1813
3	BERG	Alban	1885

Description and comments

Dela is used to delete elements (by default 1) from a set of single-sized arrays.

In every table, the elements are shifted from the end of the table (this is the default value for LIMIT) by a number of positions equal to NUMBER. The last NUMBER elements in the table are set to null values (0 for numeric values, null date for dates, and empty character strings for strings).

When LIMIT has a value that is smaller than the lowest limit of the arrays, elements from the START position to the LIMIT (inclusively) are shifted, the array elements after LIMITS are not shifted, and the NUMBER elements from position LIMIT-NUMBER+1 to LIMIT are then set to null values.

Associated errors

8	At least one of the indexes is outside the limits of one of the arrays.
10	START, NUMBER, or LIMIT are not numeric values.
50	NUMBER is less or equal to 0.
55	At least one of the arrays is not single sized.

See also

Sorta, Insa.