if.hlp

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{smcl}
{* 05apr2005}{...}
{cmd:help if}
{hline}

{title:Title}

{pstd}
{hi:[U] 11.1.3 if exp} {hline 2} if qualifier


{title:Syntax}

	{it:command} {cmd:if} {it:exp}

{pstd}
{it:exp} in the syntax diagram means an expression, such as {hi:age>21}.
See {help exp} for an explanation of expressions.

{pstd}
There is another {cmd:if} used in Stata programming; see {help ifcmd}.


{title:Description}

{pstd}
{cmd:if} at the end of a command means the command is to use only the data
specified.  {cmd:if} is allowed with most Stata commands.


{title:Examples}

{p 4 8 2}{cmd:. list make mpg if mpg>25}

{p 4 8 2}{cmd:. list make mpg if mpg>25 & mpg<30}

{p 4 8 2}{cmd:. list make mpg if mpg>25 | mpg<10}

{p 4 8 2}{cmd:. regress mpg weight displ if foreign==1}


{pstd}
Note that equality tests are performed by {cmd:==}, not a single {cmd:=};
see {help operators}.


{title:Also see}

{psee}
Manual:  {bf:[U] 11.1.3 if exp}

{psee}
Online:  {help language}; {helpb by}, {help in}
{p_end}