# if

## Purpose

Conditionally execute statements.

## Synopsis

    if expression
        statements
    end

    if expression1
        statements
    elseif expression2
        statements
    else
        statements
    end

## Description

`if` conditionally executes statements. The simple form is

    if expression
        statements
    end

The `statements` execute if the `expression` has all nonzero elements. The expression is usually the result of

    expression rop expression

where `rop` is one of ==, <, >, <=, >=, or ~=.

More complicated forms use `else` or `elseif`. Each `if` must be paired with a matching `end`.

## Examples

Here is an example showing `if`, `else`, and `elseif`:

    for i = 1:n
        for j = 1:n
            if i == j
                a(i,j) = 2;
            elseif abs([i j]) == 1
                a(i,j) = 1;
            else
                a(i,j) = 0;
            end
        end
    end

## See Also

    break, else, end, for, return, while

(c) Copyright 1994 by The MathWorks, Inc.