Do

Do(expr, {max})

evaluates expr max times.

Do(expr, {i, max})

evaluates expr max times, substituting i in expr with values from 1 to max.

Do(expr, {i, min, max})

starts with i = max.

Do(expr, {i, min, max, step})

uses a step size of step.

Do(expr, {i, {i1, i2, ...}})

uses values i1, i2, ... for i.

Do(expr, {i, imin, imax}, {j, jmin, jmax}, ...)

evaluates expr for each j from jmin to jmax, for each i from imin to imax, etc.

Examples

>> Do(Print(i), {i, 2, 4})
 | 2
 | 3
 | 4

>> Do(Print({i, j}), {i,1,2}, {j,3,5})
 | {1, 3}
 | {1, 4}
 | {1, 5}
 | {2, 3}
 | {2, 4}
 | {2, 5}

You can use Break() and Continue() inside Do:

>> Do(If(i > 10, Break(), If(Mod(i, 2) == 0, Continue()); Print(i)), {i, 5, 20})
 | 5
 | 7
 | 9

>> Do(Print("hi"),{1+1})
 | hi
 | hi

The A005132 Recaman’s sequence integer sequence

>> a = {1}; Do( If( a[ [ -1 ] ] - n > 0 && Position( a, a[ [ -1 ] ] - n ) == {}, a = Append( a, a[ [ -1 ] ] - n ), a = Append( a, a[ [ -1 ] ] + n ) ), {n, 2, 70} ); a
{1,3,6,2,7,13,20,12,21,11,22,10,23,9,24,8,25,43,62,42,63,41,18,42,17,43,16,44,15,45,14,46,79,113,78,114,77,39,78,38,79,37,80,36,81,35,82,34,83,33,84,32,85,31,86,30,87,29,88,28,89,27,90,26,91,157,224,156,225,155}

Related terms

Break, Continue, For, While

Implementation status

• ✅ - full supported

Github

• Implementation of Do