BUILT-IN MATHEMATICA SYMBOL

Do

Do[expr, {i_max}]
evaluates expr times.

Do[expr, {i, i_max}]
evaluates expr with the variable i successively taking on the values through (in steps of ).

Do[expr, {i, i_min, i_max}]
starts with .

Do[expr, {i, i_min, i_max, di}]
uses steps di.

Do[expr, {i, {i₁, i₂, ...}}]
uses the successive values , , ....

Do[expr, {i, i_min, i_max}, {j, j_min, j_max}, ...]
evaluates expr looping over different values of j, etc. for each i.

Details Details

Do uses the standard Mathematica iteration specification.
You can use Return, Break, Continue, and Throw inside Do.
Unless an explicit Return is used, the value returned by Do is Null.
Do[expr, spec] first evaluates spec, then localizes the variable specified and successively assigns values to it, each time evaluating expr.
Do effectively uses Block to localize values or variables.
In Do[expr, spec₁, spec₂] is effectively equivalent to Do[Do[expr, spec₂], spec₁].