# for

## Purpose

Repeat statements a specific number of times.

## Synopsis

    for variable = expression
        statements
    end

## Description

The general format is

    for variable = expression
        statement
        ...
        statement
    end

The columns of the `expression` are stored one at a time in the variable while the following statements, up to the `end`, are executed.

In practice, the `expression` is almost always of the form `scalar` : `scalar`, in which case its columns are simply scalars.

The scope of the `for` statement is always terminated with a matching `end`.

## Examples

Assume `n` has already been assigned a value. Create the Hilbert matrix, using `zeros` to preallocate the matrix to conserve memory:

    a = zeros(n,n)  % Preallocate matrix
    for i = 1:n
        for j = 1:n
            a(i,j) = 1/(i+j -1);
        end
    end

Step `s` with increments of `-0.1`

    for s = 1.0: -0.1: 0.0,..., end

Successively set `e` to the unit `n`-vectors:

    for e = eye(n),..., end

The line

    for V = A,..., end

has the same effect as

    for j = 1:n, V = A(:,j);..., end

except `j` is also set here.

## See Also

    break, end, if, return, while

(c) Copyright 1994 by The MathWorks, Inc.