for
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Description
 Description:
 This operator creates a For Type which is used in the forconstructs.
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 [init, condition, codeToExecute]
 Parameters:
 init: Code  loop variable definition
 condition: Code  called code returns false, leave the forloop
 codeToExecute: Code  code to be run on each loop
 Return Value:
 For Type
Examples
 Example 1:

// will output 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 (the to value being inclusive) 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 };
 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
 Groups:
 Program Flow
Notes
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 syntaxes;
for arguments
detects Boolean in each scope whilefor 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 e.g 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}; // _b = 1.#INF
 1.16 Please note the difference between the two syntaxes;
 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 array
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;
 Posted on June 3, 2020  11:45
 Lou Montana
 There is an Arma 2 issue (not present in Arrowhead nor in Arma 3) where having a capital letter in the variable name will throw an error:
for "_i" from 0 to 2 do { hintSilent str _i; }; // works for "_I" from 0 to 2 do { hintSilent str _I; }; // "variable _i is not defined" error