📊 PHP 7.x Comparison Cheat Sheet

Valid for PHP 7.0 - 7.4 – behavior is consistent across all these versions. (See results for PHP 8.x)

Operator ==
Operator ===
Operator <
Operator >
Operator <=
Operator >=
Operator <=> (spaceship)
in_array() without strict mode
Sorting flag SORT_REGULAR
Sorting flag SORT_NUMERIC
Sorting flag SORT_STRING
Sorting flag SORT_NATURAL
DateTime objects

Operator `==`

true

false

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	true	true	true	false	false	false	false	false	false	false	true	false	false	false	false	false
"0.0"	true	true	true	false	false	false	false	false	false	false	false	true	false	false	false	false
0	true	true	true	true	true	false	false	false	false	false	true	false	true	false	false	⚠
"foo"	false	false	true	true	false	false	false	false	false	false	false	true	false	false	false	false
""	false	false	true	false	true	false	false	false	false	false	true	false	true	false	false	false
" 42"	false	false	false	false	false	true	true	true	false	true	false	true	false	false	false	false
"042"	false	false	false	false	false	true	true	true	false	true	false	true	false	false	false	false
"42"	false	false	false	false	false	true	true	true	false	true	false	true	false	false	false	false
"42foo"	false	false	false	false	false	false	false	false	true	true	false	true	false	false	false	false
42	false	false	false	false	false	true	true	true	true	true	false	true	false	false	false	⚠
false	true	false	true	false	true	false	false	false	false	false	true	false	true	true	false	false
true	false	true	false	true	false	true	true	true	true	true	false	true	false	false	true	true
null	false	false	true	false	true	false	false	false	false	false	true	false	true	true	false	false
[]	false	false	false	false	false	false	false	false	false	false	true	false	true	true	false	false
[1]	false	false	false	false	false	false	false	false	false	false	false	true	false	false	true	false
stdClass	false	false	⚠	false	false	false	false	false	false	⚠	false	true	false	false	false	true

Operator `===`

true

false

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	true	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false
"0.0"	false	true	false	false	false	false	false	false	false	false	false	false	false	false	false	false
0	false	false	true	false	false	false	false	false	false	false	false	false	false	false	false	false
"foo"	false	false	false	true	false	false	false	false	false	false	false	false	false	false	false	false
""	false	false	false	false	true	false	false	false	false	false	false	false	false	false	false	false
" 42"	false	false	false	false	false	true	false	false	false	false	false	false	false	false	false	false
"042"	false	false	false	false	false	false	true	false	false	false	false	false	false	false	false	false
"42"	false	false	false	false	false	false	false	true	false	false	false	false	false	false	false	false
"42foo"	false	false	false	false	false	false	false	false	true	false	false	false	false	false	false	false
42	false	false	false	false	false	false	false	false	false	true	false	false	false	false	false	false
false	false	false	false	false	false	false	false	false	false	false	true	false	false	false	false	false
true	false	false	false	false	false	false	false	false	false	false	false	true	false	false	false	false
null	false	false	false	false	false	false	false	false	false	false	false	false	true	false	false	false
[]	false	false	false	false	false	false	false	false	false	false	false	false	false	true	false	false
[1]	false	false	false	false	false	false	false	false	false	false	false	false	false	false	true	false
stdClass	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	true

Operator `<`

true

false

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	false	false	false	true	false	true	true	true	true	true	false	true	false	true	true	true
"0.0"	false	false	false	true	false	true	true	true	true	true	false	false	false	true	true	true
0	false	false	false	false	false	true	true	true	true	true	false	true	false	true	true	⚠
"foo"	false	false	false	false	false	false	false	false	false	true	false	false	false	true	true	true
""	true	true	false	true	false	true	true	true	true	true	false	true	false	true	true	true
" 42"	false	false	false	true	false	false	false	false	true	false	false	false	false	true	true	true
"042"	false	false	false	true	false	false	false	false	true	false	false	false	false	true	true	true
"42"	false	false	false	true	false	false	false	false	true	false	false	false	false	true	true	true
"42foo"	false	false	false	true	false	false	false	false	false	false	false	false	false	true	true	true
42	false	false	false	false	false	false	false	false	false	false	false	false	false	true	true	⚠
false	false	true	false	true	false	true	true	true	true	true	false	true	false	false	true	true
true	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false
null	true	true	false	true	false	true	true	true	true	true	false	true	false	false	true	true
[]	false	false	false	false	false	false	false	false	false	false	false	true	false	false	true	true
[1]	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	true
stdClass	false	false	⚠	false	false	false	false	false	false	⚠	false	false	false	false	false	false

Operator `>`

true

false

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	false	false	false	false	true	false	false	false	false	false	false	false	true	false	false	false
"0.0"	false	false	false	false	true	false	false	false	false	false	true	false	true	false	false	false
0	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	⚠
"foo"	true	true	false	false	true	true	true	true	true	false	true	false	true	false	false	false
""	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false
" 42"	true	true	true	false	true	false	false	false	false	false	true	false	true	false	false	false
"042"	true	true	true	false	true	false	false	false	false	false	true	false	true	false	false	false
"42"	true	true	true	false	true	false	false	false	false	false	true	false	true	false	false	false
"42foo"	true	true	true	false	true	true	true	true	false	false	true	false	true	false	false	false
42	true	true	true	true	true	false	false	false	false	false	true	false	true	false	false	⚠
false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false
true	true	false	true	false	true	false	false	false	false	false	true	false	true	true	false	false
null	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false	false
[]	true	true	true	true	true	true	true	true	true	true	false	false	false	false	false	false
[1]	true	true	true	true	true	true	true	true	true	true	true	false	true	true	false	false
stdClass	true	true	⚠	true	true	true	true	true	true	⚠	true	false	true	true	true	false

Operator `<=`

true

false

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	true	true	true	true	false	true	true	true	true	true	true	true	false	true	true	true
"0.0"	true	true	true	true	false	true	true	true	true	true	false	true	false	true	true	true
0	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	⚠
"foo"	false	false	true	true	false	false	false	false	false	true	false	true	false	true	true	true
""	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true
" 42"	false	false	false	true	false	true	true	true	true	true	false	true	false	true	true	true
"042"	false	false	false	true	false	true	true	true	true	true	false	true	false	true	true	true
"42"	false	false	false	true	false	true	true	true	true	true	false	true	false	true	true	true
"42foo"	false	false	false	true	false	false	false	false	true	true	false	true	false	true	true	true
42	false	false	false	false	false	true	true	true	true	true	false	true	false	true	true	⚠
false	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true
true	false	true	false	true	false	true	true	true	true	true	false	true	false	false	true	true
null	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true
[]	false	false	false	false	false	false	false	false	false	false	true	true	true	true	true	true
[1]	false	false	false	false	false	false	false	false	false	false	false	true	false	false	true	true
stdClass	false	false	⚠	false	false	false	false	false	false	⚠	false	true	false	false	false	true

Operator `>=`

true

false

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	true	true	true	false	true	false	false	false	false	false	true	false	true	false	false	false
"0.0"	true	true	true	false	true	false	false	false	false	false	true	true	true	false	false	false
0	true	true	true	true	true	false	false	false	false	false	true	false	true	false	false	⚠
"foo"	true	true	true	true	true	true	true	true	true	false	true	true	true	false	false	false
""	false	false	true	false	true	false	false	false	false	false	true	false	true	false	false	false
" 42"	true	true	true	false	true	true	true	true	false	true	true	true	true	false	false	false
"042"	true	true	true	false	true	true	true	true	false	true	true	true	true	false	false	false
"42"	true	true	true	false	true	true	true	true	false	true	true	true	true	false	false	false
"42foo"	true	true	true	false	true	true	true	true	true	true	true	true	true	false	false	false
42	true	true	true	true	true	true	true	true	true	true	true	true	true	false	false	⚠
false	true	false	true	false	true	false	false	false	false	false	true	false	true	true	false	false
true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true
null	false	false	true	false	true	false	false	false	false	false	true	false	true	true	false	false
[]	true	true	true	true	true	true	true	true	true	true	true	false	true	true	false	false
[1]	true	true	true	true	true	true	true	true	true	true	true	true	true	true	true	false
stdClass	true	true	⚠	true	true	true	true	true	true	⚠	true	true	true	true	true	true

Operator `<=>`

Spaceship operator: Returns -1 if left is less, 0 if equal, 1 if left is greater.

-1 (less)

0 (equal)

1 (greater)

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	0	0	0	-1	1	-1	-1	-1	-1	-1	0	-1	1	-1	-1	-1
"0.0"	0	0	0	-1	1	-1	-1	-1	-1	-1	1	0	1	-1	-1	-1
0	0	0	0	0	0	-1	-1	-1	-1	-1	0	-1	0	-1	-1	⚠
"foo"	1	1	0	0	1	1	1	1	1	-1	1	0	1	-1	-1	-1
""	-1	-1	0	-1	0	-1	-1	-1	-1	-1	0	-1	0	-1	-1	-1
" 42"	1	1	1	-1	1	0	0	0	-1	0	1	0	1	-1	-1	-1
"042"	1	1	1	-1	1	0	0	0	-1	0	1	0	1	-1	-1	-1
"42"	1	1	1	-1	1	0	0	0	-1	0	1	0	1	-1	-1	-1
"42foo"	1	1	1	-1	1	1	1	1	0	0	1	0	1	-1	-1	-1
42	1	1	1	1	1	0	0	0	0	0	1	0	1	-1	-1	⚠
false	0	-1	0	-1	0	-1	-1	-1	-1	-1	0	-1	0	0	-1	-1
true	1	0	1	0	1	0	0	0	0	0	1	0	1	1	0	0
null	-1	-1	0	-1	0	-1	-1	-1	-1	-1	0	-1	0	0	-1	-1
[]	1	1	1	1	1	1	1	1	1	1	0	-1	0	0	-1	-1
[1]	1	1	1	1	1	1	1	1	1	1	1	0	1	1	0	-1
stdClass	1	1	⚠	1	1	1	1	1	1	⚠	1	0	1	1	1	0

🔍 in_array() without strict mode

Testing how in_array() finds values when strict mode is disabled (default behavior).

Needle	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	true	true	true	false	false	false	false	false	false	false	true	false	false	false	false	false
"0.0"	true	true	true	false	false	false	false	false	false	false	false	true	false	false	false	false
0	true	true	true	true	true	false	false	false	false	false	true	false	true	false	false	⚠
"foo"	false	false	true	true	false	false	false	false	false	false	false	true	false	false	false	false
""	false	false	true	false	true	false	false	false	false	false	true	false	true	false	false	false
" 42"	false	false	false	false	false	true	true	true	false	true	false	true	false	false	false	false
"042"	false	false	false	false	false	true	true	true	false	true	false	true	false	false	false	false
"42"	false	false	false	false	false	true	true	true	false	true	false	true	false	false	false	false
"42foo"	false	false	false	false	false	false	false	false	true	true	false	true	false	false	false	false
42	false	false	false	false	false	true	true	true	true	true	false	true	false	false	false	⚠
false	true	false	true	false	true	false	false	false	false	false	true	false	true	true	false	false
true	false	true	false	true	false	true	true	true	true	true	false	true	false	false	true	true
null	false	false	true	false	true	false	false	false	false	false	true	false	true	true	false	false
[]	false	false	false	false	false	false	false	false	false	false	true	false	true	true	false	false
[1]	false	false	false	false	false	false	false	false	false	false	false	true	false	false	true	false
stdClass	false	false	⚠	false	false	false	false	false	false	⚠	false	true	false	false	false	true

🔀 Sorting behavior (SORT flags)

SORT flags are used in sorting functions (sort, usort, asort, etc.) and array_unique().
When two values are considered equal (=), their relative order in the result is undefined and may vary between PHP versions or implementations.

Sorting flag `SORT_REGULAR`

< (less than)

= (equal)

> (greater than)

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	=	=	=	<	>	<	<	<	<	<	=	<	>	<	<	<
"0.0"	=	=	=	<	>	<	<	<	<	<	>	=	>	<	<	<
0	=	=	=	=	=	<	<	<	<	<	=	<	=	<	<	⚠
"foo"	>	>	=	=	>	>	>	>	>	<	>	=	>	<	<	<
""	<	<	=	<	=	<	<	<	<	<	=	<	=	<	<	<
" 42"	>	>	>	<	>	=	=	=	<	=	>	=	>	<	<	<
"042"	>	>	>	<	>	=	=	=	<	=	>	=	>	<	<	<
"42"	>	>	>	<	>	=	=	=	<	=	>	=	>	<	<	<
"42foo"	>	>	>	<	>	>	>	>	=	=	>	=	>	<	<	<
42	>	>	>	>	>	=	=	=	=	=	>	=	>	<	<	⚠
false	=	<	=	<	=	<	<	<	<	<	=	<	=	=	<	<
true	>	=	>	=	>	=	=	=	=	=	>	=	>	>	=	=
null	<	<	=	<	=	<	<	<	<	<	=	<	=	=	<	<
[]	>	>	>	>	>	>	>	>	>	>	=	<	=	=	<	<
[1]	>	>	>	>	>	>	>	>	>	>	>	=	>	>	=	<
stdClass	>	>	⚠	>	>	>	>	>	>	⚠	>	=	>	>	>	=

Sorting flag `SORT_NUMERIC`

< (less than)

= (equal)

> (greater than)

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	=	=	=	=	=	<	<	<	<	<	=	<	=	=	<	⚠
"0.0"	=	=	=	=	=	<	<	<	<	<	=	<	=	=	<	⚠
0	=	=	=	=	=	<	<	<	<	<	=	<	=	=	<	⚠
"foo"	=	=	=	=	=	<	<	<	<	<	=	<	=	=	<	⚠
""	=	=	=	=	=	<	<	<	<	<	=	<	=	=	<	⚠
" 42"	>	>	>	>	>	=	=	=	=	=	>	>	>	>	>	⚠
"042"	>	>	>	>	>	=	=	=	=	=	>	>	>	>	>	⚠
"42"	>	>	>	>	>	=	=	=	=	=	>	>	>	>	>	⚠
"42foo"	>	>	>	>	>	=	=	=	=	=	>	>	>	>	>	⚠
42	>	>	>	>	>	=	=	=	=	=	>	>	>	>	>	⚠
false	=	=	=	=	=	<	<	<	<	<	=	<	=	=	<	⚠
true	>	>	>	>	>	<	<	<	<	<	>	=	>	>	=	⚠
null	=	=	=	=	=	<	<	<	<	<	=	<	=	=	<	⚠
[]	=	=	=	=	=	<	<	<	<	<	=	<	=	=	<	⚠
[1]	>	>	>	>	>	<	<	<	<	<	>	=	>	>	=	⚠
stdClass	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠

Sorting flag `SORT_STRING`

< (less than)

= (equal)

> (greater than)

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	=	<	=	<	>	>	<	<	<	<	>	<	>	⚠	⚠	⚠
"0.0"	>	=	>	<	>	>	<	<	<	<	>	<	>	⚠	⚠	⚠
0	=	<	=	<	>	>	<	<	<	<	>	<	>	⚠	⚠	⚠
"foo"	>	>	>	=	>	>	>	>	>	>	>	>	>	⚠	⚠	⚠
""	<	<	<	<	=	<	<	<	<	<	=	<	=	⚠	⚠	⚠
" 42"	<	<	<	<	>	=	<	<	<	<	>	<	>	⚠	⚠	⚠
"042"	>	>	>	<	>	>	=	<	<	<	>	<	>	⚠	⚠	⚠
"42"	>	>	>	<	>	>	>	=	<	=	>	>	>	⚠	⚠	⚠
"42foo"	>	>	>	<	>	>	>	>	=	>	>	>	>	⚠	⚠	⚠
42	>	>	>	<	>	>	>	=	<	=	>	>	>	⚠	⚠	⚠
false	<	<	<	<	=	<	<	<	<	<	=	<	=	⚠	⚠	⚠
true	>	>	>	<	>	>	>	<	<	<	>	=	>	⚠	⚠	⚠
null	<	<	<	<	=	<	<	<	<	<	=	<	=	⚠	⚠	⚠
[]	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠
[1]	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠
stdClass	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠

Sorting flag `SORT_NATURAL`

< (less than)

= (equal)

> (greater than)

Error

	"0"	"0.0"	0	"foo"	""	" 42"	"042"	"42"	"42foo"	42	false	true	null	[]	[1]	stdClass
"0"	=	<	=	<	>	<	<	<	<	<	>	<	>	⚠	⚠	⚠
"0.0"	>	=	>	<	>	<	<	<	<	<	>	<	>	⚠	⚠	⚠
0	=	<	=	<	>	<	<	<	<	<	>	<	>	⚠	⚠	⚠
"foo"	>	>	>	=	>	>	>	>	>	>	>	>	>	⚠	⚠	⚠
""	<	<	<	<	=	<	<	<	<	<	=	<	=	⚠	⚠	⚠
" 42"	>	>	>	<	>	=	=	=	<	=	>	>	>	⚠	⚠	⚠
"042"	>	>	>	<	>	=	=	=	<	=	>	>	>	⚠	⚠	⚠
"42"	>	>	>	<	>	=	=	=	<	=	>	>	>	⚠	⚠	⚠
"42foo"	>	>	>	<	>	>	>	>	=	>	>	>	>	⚠	⚠	⚠
42	>	>	>	<	>	=	=	=	<	=	>	>	>	⚠	⚠	⚠
false	<	<	<	<	=	<	<	<	<	<	=	<	=	⚠	⚠	⚠
true	>	>	>	<	>	<	<	<	<	<	>	=	>	⚠	⚠	⚠
null	<	<	<	<	=	<	<	<	<	<	=	<	=	⚠	⚠	⚠
[]	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠
[1]	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠
stdClass	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠	⚠

📅 DateTime objects

DateTime objects support comparison operators, which many developers don't realize!

✅ DateTime supports <, >, <=, >=

$past   = new DateTime('2023-01-01');
$now    = new DateTime('2024-01-01');
$future = new DateTime('2025-01-01');

$past < $now     → true
$future > $now   → true
$now <= $now     → true

✅ == checks value equality, === checks identity

$date1 = new DateTime('2024-06-15 10:30:00');
$date2 = new DateTime('2024-06-15 10:30:00');  // same time, different object
$date3 = $date1;                               // same reference

$date1 == $date2   → true  // ✅ same timestamp
$date1 === $date2  → false // ❌ different objects
$date1 === $date3  → true  // ✅ same reference

✅ DateTime and DateTimeImmutable are comparable

$mutable   = new DateTime('2024-03-15 12:00:00');
$immutable = new DateTimeImmutable('2024-03-15 12:00:00');

$mutable == $immutable   → true  // ✅ same timestamp

📊 PHP 7.x Comparison Cheat Sheet

Operator ==

Operator ===

Operator <

Operator >

Operator <=

Operator >=

Operator <=>

🔍 in_array() without strict mode

🔀 Sorting behavior (SORT flags)

Sorting flag SORT_REGULAR

Sorting flag SORT_NUMERIC

Sorting flag SORT_STRING

Sorting flag SORT_NATURAL

📅 DateTime objects

✅ DateTime supports <, >, <=, >=

✅ == checks value equality, === checks identity

✅ DateTime and DateTimeImmutable are comparable

Operator `==`

Operator `===`

Operator `<`

Operator `>`

Operator `<=`

Operator `>=`

Operator `<=>`

Sorting flag `SORT_REGULAR`

Sorting flag `SORT_NUMERIC`

Sorting flag `SORT_STRING`

Sorting flag `SORT_NATURAL`