2 Variable & Constants
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
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| Variable | An identifier / memory location representing a value needed by the program. The value may change while the program is running.
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| Constant | When a constant is declared it must be given a value which cannot then be changed while the program is running.
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| Advantages of constants | Descriptive identifier used for a value to make code easier to write/understand. Value only needs to be changed in one place.
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| Scope of a variable | That part of a program where the variable is available. e.g. whether it is local or global. If global and local variables use the same identifier, then the local takes precedence.
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| Local variable | Declared within a subroutine/block. Only available within that sub/block. Destroyed when the sub/block exits.
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| Global variable | Declared at the beginning of a program and is available throughout the program.
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| Data Types | Integer (whole number), Real (decimal fractions), Boolean (TRUE/FALSE), Text/string (alphanumeric – a series of characters), Date. Phone number is text NOT an Integer – an integer would lose the leading zero.
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| Array | A collection of data items of the same data type stored under one identifier. Each item can be accessed via its index.
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| Declaring an array | Identifier (name), size (size -largest index), data type .e.g Dim arrNames(10) As String
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| 2D Array | A collection of data items of the same data type under one identifier. Uses two index numbers. Can be represented as a grid/table/array of arrays.
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| Advantages of arrays | Code is easier to manage/has fewer variables/can use iteration (looping). More efficient than separate variables.
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| Serial search on array | Check the array is not empty (report error if it is). Set a counter to 1/0/start from first position. Check if item (at current position) is item searched. If found return the position/value of counter. If not found increment counter/move to next position
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To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
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Created by:
Chelsea2760
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