**VARPTR$** is a memory function that returns a [STRING](STRING) representation of a variable's memory address value for use in a [DRAW](DRAW) or [PLAY](PLAY) statement. ## Syntax > string_value$ = VARPTR$(*variable*) * Can use any [STRING](STRING) or numerical variable reference **existing** in memory. * If the parameter value is from an array it must be dimensioned already. Cannot use fixed length string arrays. * When using **numerical** *variable* values in [DRAW](DRAW) strings, use an = sign after the function letter. "TA=" + VARPTR$(*variable%*) * Always use variable X as in "X" + VARPTR$(*string_variable$*) to [DRAW](DRAW) or [PLAY](PLAY) another [STRING](STRING) value. * DRAW relative Moves use a + or - before the equal sign. EX: DRAW "M+=" + VARPTR$(x%) + ",-=" + VARPTR$(y%) ## Example(s) How VARPTR$ reads consecutive values from memory. ```vb SCREEN 2 CLS WIND$ = "r10 d7 l10 u7 br20" 'create draw string to be read by function ROW$ = "x"+VARPTR$(WIND$)+"x"+VARPTR$(WIND$)+"x"+VARPTR$(WIND$)+" x"+VARPTR$(WIND$)+"bl80 bd11" LINE (100, 50)-(200, 160), , B DRAW "bm 115,52" FOR I = 1 TO 10 DRAW "x" + VARPTR$(ROW$) NEXT ``` > *NOTE:'GWBasic** allows **semicolons** to be used in the ROW$ definition, but QBasic and **QB64** MUST use **+** concatenation. Using the function to change a Turn Angle value using DRAW. ```vb SCREEN 12 'Demonstrates how string DRAW angles are used with TA FOR i = 0 TO 360 STEP 30 'mark clock hours every 30 degrees angle$ = STR$(i) 'change degree value i to a string PSET (175, 250), 6 'clock center DRAW "TA" + angle$ + "BU100" 'add string angle to Turn Angle and draw blind up CIRCLE STEP(0, 0), 5, 12 'place a circle at end of Up line DRAW "P9, 12" _DELAY .5 NEXT 'Demonstrates how VARPTR$ is used with TA= DO: sec$ = RIGHT$(TIME$, 2) 'get current second value from time degree = VAL(sec$) * -6 'use a negative value to Turn Angle clockwise PSET (175, 250), 9 'clock center DRAW "TA=" + VARPTR$(degree) + "U90" 'VARPTR$ value requires = in DRAW DO: _LIMIT 30: LOOP UNTIL RIGHT$(TIME$, 2) <> sec$ 'loop until seconds value changes IF INKEY$ <> "" THEN EXIT DO PSET (175, 250), 0 DRAW "TA=" + VARPTR$(degree) + "U90" 'erase previous second hand draw LOOP ``` > *Explanation:* When the VARPTR$ value is used in DRAW, **=** MUST be used to pass the value to the draw! Negative Turn Angle values move clockwise and each second moves the hand 6 degrees. **TA** uses actual degree angles starting at 0 or noon. Comparing DRAW moves using VARPTR$ and [STR$](STR$) values. ```vb SCREEN 12 PSET (200, 200), 12 CIRCLE STEP(0, 0), 5, 10 A = 100: B = 100 DRAW "M+=" + VARPTR$(A) + ",-=" + VARPTR$(B) PSET (400, 400), 10 CIRCLE STEP(0, 0), 5, 12 C = 100: D = -100 DRAW "M+" + STR$(C) + "," + STR$(D) 'must add + for positive relative moves END ``` > *Explanation:* A negative STR$ value will move the DRAW relatively where VARPTR$ won't without the sign before the equal. ## See Also * [VARPTR](VARPTR), [STR$](STR$) * [DRAW](DRAW), [PLAY](PLAY)