| Property | Value |
|---|---|
| Hex Value | $72 |
| Categories | |
| Localizations |
|
Ans
Overview
Returns the last answer.
Availability: Token available everywhere.
Syntax
Ans
Location
2nd, ans
Description
The Ans variable holds the last answer that was stored in the calculator. Because Ans is stored in a special storage area built-in to the calculator, and it is extensively used by the calculator, you cannot delete it. Ans is also useful; it can make your programs both smaller and faster:
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Unlike other variables which have a value type hard-coded in (i.e., a string can only hold text, and lists and matrices can only hold numbers), Ans can take on whatever value you want: a real or complex, list, matrix, or string are all acceptable.
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Along with the finance variables, Ans is faster than the real, complex, list, matrix, and string variables; and subsequently, you should try to use it as much as possible.
One of the most common places to use Ans is in place of storing a value to a variable. Just paste the Ans variable to the location where the variable was called, and then when the expression is evaluated, the calculator will use the current value of Ans. Using the Ans variable allows you to eliminate the variable, which helps save a little or a lot of memory (depending on the type of variable and its size).
Instead of:
30+5A→B
Disp 25A,B
A shorter version would be:
30+5A
Disp 25A,Ans
(Since the Ans token is only 1 byte, you've just saved two bytes. In longer programs the savings can add up!)
The one major drawback to using Ans is that its current value is only temporary.
What commands modify Ans?
Whenever you:
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Store a value to a variable, such as 1→X
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Place an expression or string on a line by itself, such as 1+2 or "Hello"
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Use the optional argument of the Pause command such as Pause X. Ans will be updated to the new value.
If you're performing multiple calculations across multiple variables, you might be better off storing each in a separate variable.
What commands do NOT modify Ans?
There are several cases in which changing the value of a variable does not modify Ans, thus preserving its current value for later use:
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Asking a user for input via Prompt X or Input "X:",X
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Storing to an equation variable such as "X+1"→Y₁
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Using DelVar to delete a variable (i.e. set its value to zero, if it's a real variable)
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For( loops
Also most other commands that do not modify variables will preserve Ans, including:
- ClrHome
- If … Then … Else … End
- Disp
- Output()
- Repeat
- While
- Lbl
- Goto
- Menu()
- Pause (when there's no parameter following it, otherwise the parameter will be stored in Ans!)
Knowing these cases can be very useful, allowing you to make efficient use of Ans to store a result and re-use it in later lines rather than create a temporary variable for it.
Using Ans with Lists
Ans can be used to store lists and access individual items. Take the following example:
10→A
{11,22,33}
Disp Ans(1),Ans(2)
In this example, the calculator is smart enough to know that Ans is currently holding a list, and so will interpret the (1) and (2) as accessing items from the list. As such it will display 11 and 22. Trying to access Ans(4) will display an error.
However if we removed line 2 from the code above, Ans would instead be holding the value 10, and as such Ans would be multiplied by 1 and 2, resulting in 10 and 20.
The augment() function can also be used with Ans to add additional items to your list, for example:
{1,2}
augment(Ans,{3,4})
Disp Ans
This will display {1 2 3 4}
Timing
Storing a real value into Ans takes approximately 1.0 ms. This does not include the time needed to compute or retrieve the value, which may be significant.
Source: parts of this page were written by the following TI|BD contributors: alexrudd, burr, DarkerLine, GoVegan, kg583, lirtosiast, Myles_Zadok, rileyp, Timothy Foster, Trenly.
History
| Calculator | OS Version | Description |
|---|---|---|
| TI-82 | 1.0 | Added |