Comparison Operators
Comparison operators, as their name implies, allow you
to compare two values.
表格 11-4. Comparison Operators
Example |
Name |
Result |
$a == $b |
Equal |
TRUE if $a is equal to
$b. |
$a === $b |
Identical |
TRUE if $a is equal to $b, and
they are of the same type. (PHP 4 only) |
$a != $b |
Not equal |
TRUE if $a is not equal to
$b. |
$a $b |
Not equal |
TRUE if $a is not equal to
$b. |
$a !== $b |
Not identical |
TRUE if $a is not equal to $b,
or they are not of the same type. (PHP 4 only) |
$a $b |
Less than |
TRUE if $a is strictly less
than $b. |
$a $b |
Greater than |
TRUE if $a is strictly greater
than $b. |
$a = $b |
Less than or equal
to |
TRUE if $a is less than or
equal to $b. |
$a = $b |
Greater than or
equal to |
TRUE if $a is greater than or
equal to $b. |
Another conditional operator is the "?:" (or ternary)
operator, which operates as in C and many other
languages.
This expression evaluates to
expr2 if
expr1
evaluates to
TRUE, and
expr3 if
expr1 evaluates to
FALSE.