basic-02.md

Basics-02

• Get to your submission folder under exercises/php-basics-01
• You should create a PHP file for each step with the name of the step.

e.g : Step_1.php

• COMMIT AFTER EACH STEP, call each commit by the name of the step

References

• https://www.codecademy.com/courses/learn-php
• https://phptherightway.com/
• https://www.sololearn.com/Course/PHP/

Goals

• Learn general basic programming syntax as applied to PHP
• Competencies:
  • Echo
  • Functions
  • Variables
  • PHP Built in functions

Step 1

Write a PHP script to display the following strings.

You can only use Echo or Print.

Expected Output :

Tomorrow I 'll learn PHP global variables.
This is a bad command: sudo rm -rf /

...

Step 2

Write a PHP function to test whether a number is greater than 30, 20 or 10

Sample:

<?php

function greaterFn($num){
  // ...
  return 'string';
}
greaterFn(40); // 40 is greater than 30
greaterFn(21); // 21 is greater than 20
greaterFn(12); // 12 is greater than 10
greaterFn(8);  // 8 is less than 10

Step 3

Write a PHP program to swap two variables.

Example:

$var1 = 32;
$var2 = 45;

...

$var1; // 45
$var2; // 32

...

Step 4

Write a PHP program to check whether a number is an Armstrong number or not. Return true if the number is Armstrong otherwise return false.

In PHP a double star ( ) is an Exponentiation operator, 2 ^ 5 === 2 5 | 2 ^ 2 === 2 ** 2

Note: An Armstrong number of three digits is an integer so that the sum of the cubes of its digits is equal to the number itself.

For example, 153 is an Armstrong number since 1 3 + 5 3 + 3 ** 3 = 153

...

Step 5

Write a PHP program(function) to convert word to digit. Use switch case.

Input: zero
Output: 0

Input one
Output 1

Input: five
Output: 5

...

Step 6

Write a PHP program to compute the sum of the digits of a number.

Hint: Input $num = '54321'; $num[0]; // 5, $num[3] // 2

Use strlen($num) to get the length of the string

...

Step 7

Write a PHP program to replace a string "Python" with "PHP" and "Python" with " PHP" in a given string.

Input: English letters (including single byte alphanumeric characters, blanks, symbols) are given on one line. The length of the input character string is 1000 or less.

Use str_replace

...

Step 8

Write a PHP program to check whether a given positive integer is a power of two.

Input : 4

Output :4 is power of 2

Step 9

Write a PHP program to compute and return the square root of a given number.

Input: 16
Output: 4

...

Step 10

Write a PHP function that checks whether a passed string is a palindrome or not?

A palindrome is word, phrase, or sequence that reads the same backward as forward, e.g., madam or nurses run.

Hint use strrev. strrev("Hello"); // olleH ...

Step 11

Write a function to check whether a number is prime or not.

Note: A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.

...

Hints

• Writing a programme mean that you need to create a function
• Writing a script mean that you aren't required to write a function