Strings

Question 1

What is the difference between ‘’ y “” ?

Answer 1

Que en “” puedo poner la variable directo sin concatenar:

“mi nombre es $nombre”

Question 2

How do you get the length of a string?

Answer 2

strlen($string)

Question 3

How do you trim a string?

Answer 3

trim($string)

Question 4

How do you trim the left side of a string?

Answer 4

ltrim($string)

Question 5

How do you trim the right side of a string?

Answer 5

rtrim($string)

Question 6

How do you count the number of words of a string?

Answer 6

str_word_count($string)

Question 7

How do you reverse a string?

Answer 7

strrev($string)

Question 8

How do you make the entire string into uppercase?

Answer 8

strtoupper($string)

Question 9

How do you make the entire string into lowercase?

Answer 9

strtolower($string)

Question 10

How do you make the first character uppercase?

Answer 10

ucfirst($string)

Question 11

How do you make the first character lowercase?

Answer 11

lcfirst($string)

Question 12

How do you capitalize the first char of every word?

Answer 12

ucwords($string)

Question 13

How do you find the index of a word?

Answer 13

strpos($string,’word’)

Question 14

How do you find the index of a word no without taking into account capitalization?

Answer 14

stripos($string,’word’)

Question 15

How do I get a substring from a certain index?

Answer 15

substr($string,index)

Question 16

How do I replace a word for another one in a string?

Answer 16

str_replace(‘word’,’php’,$string)

Question 17

Ho do I replace a word for another on without taking into account capitalization?

Answer 17

str_replace(‘word’,’php’,$string)

Question 18

How do you do a multi line text?

Answer 18

$string=”
hello,
this is multi
line.
“

then nl2br($string);

this will set it multiline when printing.

Question 19

How do you use htmlentities and what do you useit for?

Answer 19

Se usa para que convierta los caracteres reservados en html entities. por ejemplo para que convierta < en <
entonces si hago htmlentities(‘<b>Hello</b>’) en el html lo va a tomar como <b>Hello</b> y en lo que muestra en el browser lo va a mostrar literalmente <b>Hello</b> sin hacer el negrita.

Question 20

Si tengo un texto donde los caracteres reservados fueron convertidos a html entities, como hago para que vuelvan a ser caracteres reservados?

Answer 20

uso html_entity_decode(<b>Hello</b>) y eso va a hacer que se lea en negrita.