Arithmetic

The operators

xTalk uses the symbols you know from maths, with * for times, / for divide and ^ for "to the power of".

put 7 + 5
put 7 - 5
put 7 * 5
put 7 / 5
put 2 ^ 10

12
2
35
1.4
1024

Whole numbers: div and mod

div divides and drops the part left over. mod gives only what is left over. They are more useful than they look: mod 2 tells you whether a number is even, and the pair turns seconds into minutes and seconds.

put 17 div 5
put 17 mod 5
put 10 mod 2 -- 0: 10 is even
put 125 div 60 & ":" & 125 mod 60
put 200 div 60 && "hours" && 200 mod 60 && "minutes"

3
2
0
2:5
3 hours 20 minutes

Which goes first

As in maths, ^ comes first, then *, /, div and mod, then + and -. Operators of the same kind go from left to right. Brackets change the order, and make a long sum easier to read even when they do not.

put 2 + 3 * 4
put (2 + 3) * 4
put 10 - 4 - 3
put 2 * 3 ^ 2
put (2 * 3) ^ 2

14
20
3
18
36

Decimals

Division gives decimals when it needs them. xTalk keeps many digits, but shows at most six decimal places unless you ask for more.

put 10 / 4
put 10 / 3
put 0.1 + 0.2
put 0.1 + 0.2 = 0.3

2.5
3.333333
0.3
true

Changing a number in place

Four commands change the number in a variable directly. They read like the sentences you would say:

put 100 into tMoney
add 20 to tMoney
subtract 5 from tMoney
multiply tMoney by 2
divide tMoney by 10
put tMoney

23

add 1 to tCount is the xTalk way of counting: you will see it in nearly every program with a loop. A variable that has nothing in it counts as 0, so you do not even need to start it at 0 first.

Dividing by zero

A number divided by zero has no answer, so xTalk stops with an error rather than make one up.

put 0 into tPlayers
put 100 / tPlayers

When a value might be zero, check it first with if (the subject of Making decisions).

put 137 into tMinutes
put tMinutes div 60 && "hours" && tMinutes mod 60 && "minutes"
put 7 * 24 * 60 * 60

2 hours 17 minutes
604800