for

-wrong parameter ("Arma") defined!-1.00

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Description

Description:

This operator creates a For Type which is used in the for-constructs.

⚠

Alternative syntax for array do code is slower and should not be used.

Groups:

Uncategorised

Syntax

Syntax:

for arguments

Parameters:

arguments: String - declares the index variable name like "_myVar". from and to are required, step is optional.

Return Value:

For Type

Alternative Syntax

Syntax:

for array

Parameters:

array: Array - a 3-dimensional array of Code as follow: [init, condition, codeToExecute]

Return Value:

For Type

Examples

Example 1:

for "_i" from 1 to 10 do { systemChat str _i; };

Example 2:

for "_i" from 9 to 1 step -2 do { systemChat str _i; };

Example 3:

for [{ _i = 0 }, { _i < 10 }, { _i = _i + 1 }] do { systemChat str _i }; // deprecated, should not be used

Example 4:

// BAD CODE _i = 100; for [{_i = 0}, {_i < 5}, {_i = _i + 1}] do {}; hint str _i; // 5 // GOOD CODE (private keyword is recommended) _i = 100; for [{private _i = 0}, {_i < 5}, {_i = _i + 1}] do {}; hint str _i; // 100

Additional Information

See also:

Control Structureswhiledo

Notes

Report bugs on the Feedback Tracker and/or discuss them on the Arma Discord or on the Forums.
Only post proven facts here! Add Note

Notes

Posted on 29 April 2010 (CEST)

alef

for "_i" from 0 to 0 do {}; // will do once, with _i = 0 for "_i" from 0 to -1 do {}; // will not do

Posted on Apr 15, 2014 - 12:54

ffur2007slx2_5

• 1.16 Please note the difference between the two syntaxed; for arguments detects Boolean in each scope while for array doesn’t. e.g.

command	Structure	Summary
for array	a = 0; b = true; for [{ _i = 0 }, { _i < 10 && b }, { _i = _i + 1 }] do { a = a + 1; if (a >= 7) then {b = false} }	loop can be exited via Boolean control, possible workaround can be like BIS_fnc_areEqual
for arguments	a = 0; for "_i" from 0 to 10 do { a = a + 1; if (a >= 7) exitwith {} };	has to be exited via exitWith

• Never try to tell a decimal number via binary number in a loop; otherwise the loop will be infinite:

for [{_a = 0},{_a != 1},{_a = _a + 0.1}] do {}; // an infinite loop; _a will never be 1 so the scope will always be true Any binary number behind the decimal point is always the sum of 1/2, 1/4, 1/8, 1/16 etc. so decimal number with odd denominator like 1/3 or 1/10 cannot be exactly equal to each other.

• Avoid too large factorial multiply which may loose the leading indicator in result. And 12 is the biggest accessable factor in this example.

for [{_a = 2; _b = 1;},{_a < 100},{_a = _a + 1}] do {_b = _b * _a}; -no comment defined-

Posted on June 4, 2015 - 19:27 (UTC)

Killzone Kid

Variable name doesn't have to start with _. could be:for "LAlala" from 0 to 0 do {hint str LAlala}; // 0 The variable LAlala will exist only inside do {} scope and will not overwrite any variable of the same name that existed before.

Posted on June 4, 2015 - 19:45 (UTC)

Nickorr

Dont use this notation if you plan to change the cycle ranges dynamically. The range values are checked only before the cycle started. Use for_forspec instead.
Example, that won't work correctly: _xy = [1,2,3,4,5,6,7,8,9,10]; for "_i" from 0 to (count _xy - 1) do { if ( _xy select _i == 3 ) then { _xy deleteAt _i; _i = _i - 1; }; }; (Here the _i = 9 step will still be checked by the cycle, which will lead to "out of the array range" error.)
This code will work correctly: _xy = [1,2,3,4,5,6,7,8,9,10]; for [{_i=1},{_i<=(count _xy - 1)},{_i=_i+1}] do { if ( _xy select _i == 3 ) then { _xy deleteAt _i; _i = _i - 1; }; }; (The last step here will be _i = 8 with array looking like this: [1,2,4,5,6,7,8,9,10])

Posted on January 29, 2016 - 05:18 (UTC)

DreadedEntity

For loops can be safely nested. This means that there should not be any problems with recursion. _array = []; for "_i" from 0 to 3 do { for "_i" from 0 to 3 do { _array pushBack _i; }; _array pushBack _i; }; hint str _array;