Privacy Policy
Support

USERNAME

PASSWORD

>>> SIGN UP!

Lost Password?

PROGRAMMING BASICS

RSS

A Tour of Decision Making Structures in PHP

By: bluephoenix	Search For More Articles! Disclaimer Author Terms
Rating: / 3
2003-10-19

Table of Contents:

A Tour of Decision Making Structures in PHP

Comparison Operators

IF Statements

SWITCH-CASE statements

Conclusion

SEARCH CODEWALKERS

TOOLS YOU CAN USE

A Tour of Decision Making Structures in PHP - Comparison Operators

(Page 2 of 5 )

The following chart shows some common operators you may use in your programs.

operator    comparison
------------------------------------------------
  x == y    checks if the value of x is equal to
            the value of y

  x != y    checks if the value of x is not
            equal to the value of y

  x &lt; y     checks if the value of x is less
            than the value of y

  x &gt; y     checks if the value of x is greater
            than the value of y

  x &lt;= y    checks if the value of x is less
            than or equal to the value of y

  x &gt;= y    checks if the value of x is greater
            than or equal to the value of y

(a) &amp;&amp; (b)  checks if the value of statement a
            and statement b evaluate to "true"

(a) || (b)  checks if the value of statement a
            or statement b evaluate to "true"

Let's apply that information to some example comparisons. Assuming $x holds the value 5, $y holds 100 and $z holds 500:

($x == $y) &amp;&amp; ($x &lt;= $z)
(5 == 100) &amp;&amp; (5 &lt;= 500)
   false   &amp;&amp;    true
&gt;  false

($x * $y) == $z
(5 * 100) == 500
   500    == 500
&gt;  true

($x != $y) || ($y == $z)
(5 != 100) || (100 == 500)
   true    ||    false
&gt;  true

Be sure that you don't confuse = with ==. = assigns a value to a variable while == compares for equality. This can be a source of great frustration for many new programmers until they become more accustomed to working with them.

Next: IF Statements >>

More Programming Basics Articles
More By bluephoenix

blog comments powered by Disqus

PROGRAMMING BASICS ARTICLES

- Control Flow Constructs
- More Time Manipulation with PHP
- Validating and Manipulating Dates with PHP
- Using the Date Constructor in PHP
- Calendar Construction with PHP
- PHP`s Calendar Package
- Getting Modified Versions and Correct Dates ...
- Combining Date Functions in PHP
- Using PHP for Date and Time in Programming
- More Exception Handling with PHP
- Exception Handling in PHP
- Error Logging and Handling Exceptions
- Configuration Directives for Error and Excep...
- Error and Exception Handling
- Python Modules for Games

Find More Programming Basics Articles