Intro to PHP

Question 1

echo does what?

Answer 1

prints something out

Question 2

what is echo format?

Answer 2

echo “text or content to be printed”;

Question 3

what do we put at end of echo statement?

Answer 3

a ; so it looks like this: echo “text or content to be printed”;

Question 4

what is a variable?

Answer 4

a variable is a container for a value - it can be declared once and then re-used.

Question 5

how do we define a variable?

Answer 5

with a $

Question 6

example of a variable?

Answer 6

$characterName = “joe” note text uses quotation marks

Question 7

how is php executed?

Answer 7

in order

Question 8

What would happen after line 6 and why?
“;
echo “He was $characterAge <br></br>”;
$characterName = “Mike”;
echo “He liked $characterName<br></br>”;
echo “Did not mind being $characterAge”;
?>

Answer 8

Name would change to Mike because this line changed the variable:
$characterName = “Mike”;

Question 9

What is the difference between storing text and numbers in a variable?

Answer 9

text uses “”, numbers don’t need quotes

Question 10

what is a string in php?

Answer 10

a string is plain text

Question 11

a string always needs?

Answer 11

””

Question 12

2 types of numbers as variables?

Answer 12

integer is a whole number - no decimal point

floating point number or floats has a decimal

Question 13

A boolean

Answer 13

is a true or false value

Question 14

Example of a boolean?

Answer 14

$isMale = true (can be true or false)

Question 15

the 5 types of variables we just learned?

Answer 15

string is text with ""
integer is a whole number
a floating point number or floats has a decimal
a boolean is true or false
null has no value

Question 16

a string is?

Answer 16

plain text

Question 17

example of printing out a string

Answer 17

echo “my string”;

Question 18

can use a variable as a container for a string?

Answer 18

yes for example: $phrase = “toasty toes”;

Question 19

how to print the toasty toes?

Answer 19

echo $phrase;

Question 20

a function can modify a string

Answer 20

yes

Question 21

what’s a function to change a string to lower case?

Answer 21

echo strtolower($phrase);

Question 22

True or False? functions are used to find out information about and to modify strings

Answer 22

true

Question 23

what’s a function to change a string to upper case?

Answer 23

echo strtoupper($phrase);

Question 24

what does a string function do? Can find out information about string or modify a string. They seem to start with?

Answer 24

str then the function - so strtolower changes to lower case

Question 25

what do we have to put around the string to use a function?

Answer 25

() - it looks like this: echo strtolower ($phrase);

Question 26

Can you use strtolower on a string that is not a variable?

How? What do we put around the string?

Answer 26

Yes, it would look like this:
echo strtolower (“Camel Towing”);
We put parens around the string ()

Question 27

What is a function to tell use the length of a string?

Answer 27

strlen. So, strlen ($phrase);

Question 28

What is an index and how is it called?

Answer 28

An index will tell us which character is in which space. This will tell us that the first character is “G” if the string is Giraffe Academy. echo $phrase[0];

Question 29

How is the index numbered? 0 is 1, 1 is 2 and so on. Giraffe?

Answer 29

Giraffe 0=G 1=i 2=r and so on.

Question 30

Also can use index function on plain strings: “Mike”

Answer 30

echo “Mike”[2]; will print out k

Question 31

What would this do?
$phrase = “Giraffe Academy”;
$phrase[0] = “B”;
echo $phrase;

Answer 31

Print out the variable as “Biraffe Academy”

It changes the character in position 0 “G” to “B”

Question 32

How to replace a part of a string? Command and example?

Answer 32

str_replace
if $phrase ="Giraffe Academy";
echo str_replace ("Giraffe", "Panda", $phrase);

Question 33

Another str_replace example?

Answer 33

if $phrase ="Cat Fish";
echo str_replace ("Cat", "Dog", $phrase);
would print out
Dog Fish

Question 34

what does substr do?

Answer 34

The substr() function is used to cut a part of a string from a string, starting at a specified position.

Question 35

What would this do? 
$phrase = "Giraffe Academy";
echo substr ($string, 8);

Answer 35

It would grab the string values starting a index position 8 and print it - in this case Academy

Question 36

What would this do? 
$phrase = "Giraffe Academy";
echo substr ($string, 8, 3);

Answer 36

It would grab the string values starting a index position 8 and print it to 3 positions out - in this case in would print Aca

Answer 37

Output

3

Question 38

Example

Answer 38

Output

Welcome to the programming world

Question 39

How to print a number?

Answer 39

echo 40;

prints out 40

Question 40

What would this print?

Answer 40

echo 5 + 9;

prints 14

Question 41

What does this do?

echo 10 % 3;

Answer 41

Prints the modulus so, 10 /3 is 3, with a remainder of 1

Prints 1

Question 42

echo 4 + 5 * 3;

Answer 42

gives us 19

Question 43

but echo (4 + 5) * 3;

Answer 43

gives us 27 - PEMDAS order matters