This is my first php program!

Comparison Operators
As their name suggests, comparison operators compare operands. The result is
always either
true
, if the comparison is truthful, or
false
, otherwise.
Operands to the comparison operators can be both numeric, both string, or one
numeric and one string. The operators check for truthfulness in slightly different
ways based on the types and values of the operands, either using strictly numeric
comparisons or using lexicographic (textual) comparisons. Table 2-7 outlines when
each type of check is used.
Table 2-5. Autoincrement and autodecrement operations
Operator
Name
Value returned
Effect on $var
$var++
Post-increment
$var
Incremented
++$var
Pre-increment
$var + 1
Incremented
$var--
Post-decrement
$var
Decremented
--$var
Pre-decrement
$var – 1
Decremented
Table 2-6. Autoincrement with letters
Incrementing this
Gives this
"a"
"b"
"z"
"aa"
"spaz"
"spba"
"K9"
"L0"
"42"
"43"
,ch02.15294 Page 39 Wednesday, March 13, 2002 11:42 AM

---

This is the Title of the Book, eMatter Edition
Copyright © 2002 O’Reilly & Associates, Inc. All rights reserved.
40
|
Chapter 2: Language Basics
One important thing to note is that two numeric strings are compared as if they were
numbers. If you have two strings that consist entirely of numeric characters and you
need to compare them lexicographically, use the
strcmp( )
function.
The comparison operators are:
Equality (
==
)
If both operands are equal, this operator returns
true
; otherwise, it returns
false
.
Identical (
===
)
If both operands are equal and are of the same type, this operator returns
true
;
otherwise, it returns
false
. Note that this operator does
not
do implicit type
casting. This operator is useful when you don’t know if the values you’re com-
paring are of the same type. Simple comparison may involve value conversion.
For instance, the strings
"0.0"
and
"0"
are not equal. The
==
operator says they
are, but
===
says they are not.
Inequality (
!=
 or
<>
)
If both operands are not equal, this operator returns
true
; otherwise, it returns
false
.
Not identical (
!==
)
If both operands are not equal, or they are not of the same type, this operator
returns
true
; otherwise, it returns
false
.
Greater than (
>
)
If the lefthand operator is greater than the righthand operator, this operator
returns
true
; otherwise, it returns
false
.
Greater than or equal to (
>=
)
If the lefthand operator is greater than or equal to the righthand operator, this
operator returns
true
; otherwise, it returns
false
.
Less than (
<
)
If the lefthand operator is less than the righthand operator, this operator returns
true
; otherwise, it returns
false
.
Less than or equal to (
<=
)
If the lefthand operator is less than or equal to the righthand operator, this oper-
ator returns
true
; otherwise, it returns
false
.
Table 2-7. Type of comparision performed by the comparision operators