1. PHP is a loosely typed scripting language that is case sensitive. It uses variables prefixed with $ to store values of different data types like strings, integers, floats, booleans, arrays and objects. 2. PHP supports many control structures like conditional statements, loops and functions. Functions allow grouping reusable blocks of code and can take arguments and return values. 3. Arrays can be indexed or associative and store multiple values. Multidimensional arrays can hold arrays within arrays.

1. PHP 101
19/4/21

2. < ? php
echo
"
hello
"
;
? >

3. * start with
Variables character .
-
.
*starts with $ sign ,
then name .
* loosely typed language
.
* case sensitive
$ filename = "h"
;
•-~
number
$number = 1 i
2 i
10 i
10-111 i

4. $ filename
=
"$fikme@
←
¥EÉ

5. Variable scope
-
local
-
global
-
static

6. Data Types
-
string
-
sequence of
character
-
integer
-
-
1000 → tooo
- float
-
10.365
- boolean
-
true / false
-
Array
-
array
( a-
"
.
"
-
"
.
"
-
"
I /[
"
-
: : : :]
-
Object
-
instance of a class
-
NULL
-
null ← no
value

7. Casting / Changing Data Type
float to integer
$ ✗ =
234.768 :
4- int-
cast = ( int) $x ;
11 $ ✗ → 234
float to string
$string-
cast =
"
$✗
"
;
string to integer
$ int-
cast =
intra ( $ string -
cast )

8. Constants
define (
"
TYPE
"
,
"
ABCD
"
);
echo
TYPE ;

9. Operators -
comparison
Equal ==
Identical ===
Not equal !=
< >
Not identical !==
G- T >
LT
<
G- Tor E > =
LT or E < =
spaceship ( =
>

10. Operators ( Logical )
true when both are true
and &&
true when either one true
or
11
true if either is true
,
butnot
✗or
both .

11. Operators ( conditional assignment )
Ternary ? :
$✗=pT④ ? exp
2 : etp3
true✓fa1R✓
Null ? ? $4 = exp 1 ?
?e
?⃝
coalescing
if exp 7- →
ist & not Null .

12. conditional statement .
if C- > {
} else if ( ) {
} else {
}

13. Conditional statement .
switch .
switch Cn ){
case label 1 :
I -
break ;
case label 2 :
-
if different
from
[ break :
defaulting
✓ any
cases .
}

14. FOR Loops
✗ =o ; sloe < =/ oo ; sloe -1-1 ) {
✗ start from $n=o →
Isn ⇐ too
with
du increment by 7- .
}
foreach ( $ array
as frat ){
}
for each [ $ array
as lskey
dual ){
}

15. FOR with Break / continue .
-
-
go out of loop . skip one loop
stop the loop .
get the last value.

16. Array ( Indexed Array )
- -1-1-1 -
¥ :
key $ array [ 0
] →
"
a
"
§
→
"
s
"
;

17. get
the length of an
array .
$ cars = E
"
-
"
,
"
-
"
,
"
-
"
]
Count ( Stears)
→ 3

18. Array as Dictionary / Associative Array
$ update [
'
image
'
] =
"
-
"
:
-
¥
.EE#ED
image
.

19. stage - list --
[
"
peter
" "
35
"
,
"
Ben
" "
37
"
,
"
fore
"
"
43
"
]
-
same
to -
stage-
list [
'
Peter
'
] =
"
35
"
;
stage-
list [
I Ber
'
] =
"
57
"
;
stage-
list [
'
Toe
'
I =
"
43
"
;

20. Multi -
Dimensional Arrays
[
[
"
-
"
,
"
-
"
i -
"
] ,
[
"
-
"
,
"
-
"
i -
"
] ,
[
"
-
"
,
"
-
"
i -
"
] ,
y
[
"
-
"
,
"
-
"
,
"
-
"
] ,

21. Function
•
a set of instructions confined to achieve
specific result.
'
can be used repeatedly
.
function
say Hi C) {
echo
"
hi
"
;
}

22. Function with
sparame③
real value
function say Namef
$naÉm"Joe
"
) ;
echo
"
Hello $=
"
i
3
function say Name Age ( $ name
, stage) {
echo
"
Hello & name
,
stage
"
;
}

23. Default Argument Value (if not passed any value )
function say Hello Name ( $ name
=
"
world
"
){
echo
"
hello §name
"
;
3

24. Function with Returning Value
function sumciat ✗ ,
int g) {
$ 2- = $ ✗ + sly ;
return $7 ;
}
echo sum ( 2,4 ) :

25. Function with Returning Value ( with Type)
function addNumbers ( float $9 ,
that $b) : float {
return Isa + Fbi
|
3
add :
Type

26. Pass Argument & Change the variable .
function add -
five ( & $ value ) {
$ value + = 5 i
}
$ nvm
= 2 I
add -
five ( strum );
11 lsnum → 7