{"id":7334,"date":"2019-10-21T06:36:42","date_gmt":"2019-10-21T06:36:42","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=7334"},"modified":"2021-11-16T05:44:21","modified_gmt":"2021-11-16T05:44:21","slug":"complete-reference-guide-of-php-operators-control-structures","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/complete-reference-guide-of-php-operators-control-structures\/","title":{"rendered":"Complete reference guide of PHP Operators & Control Structures!"},"content":{"rendered":"\n

What is Operators in PHP<\/h2>\n\n\n\n

Operators are symbols that tell the PHP processor to perform certain actions. For example, the addition (+<\/code>) symbol is an operator that tells PHP to add two variables or values, while the greater-than (><\/code>) symbol is an operator that tells PHP to compare two values.<\/p>\n\n\n\n

The following lists describe the different operators used in PHP.<\/p>\n\n\n\n

PHP Arithmetic Operators<\/h2>\n\n\n\n

The arithmetic operators are used to perform common arithmetical operations, such as addition, subtraction, multiplication etc. Here’s a complete list of PHP’s arithmetic operators:<\/p>\n\n\n\n

Operator<\/th>Description<\/th>Example<\/th>Result<\/th><\/tr>
+<\/code><\/td>Addition<\/td>$x + $y<\/code><\/td>Sum of $x and $y<\/td><\/tr>
-<\/code><\/td>Subtraction<\/td>$x - $y<\/code><\/td>Difference of $x and $y.<\/td><\/tr>
*<\/code><\/td>Multiplication<\/td>$x * $y<\/code><\/td>Product of $x and $y.<\/td><\/tr>
\/<\/code><\/td>Division<\/td>$x \/ $y<\/code><\/td>Quotient of $x and $y<\/td><\/tr>
%<\/code><\/td>Modulus<\/td>$x % $y<\/code><\/td>Remainder of $x divided by $y<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\n\nThe following example will show you these arithmetic operators in action:\n\n<\/p>\n\n\n

<?php<\/span>\n$x = 10<\/span>;\n$y = 4<\/span>;\necho<\/span>($x + $y); \/\/ 0utputs: 14<\/span>\necho<\/span>($x - $y); \/\/ 0utputs: 6<\/span>\necho<\/span>($x * $y); \/\/ 0utputs: 40<\/span>\necho<\/span>($x \/ $y); \/\/ 0utputs: 2.5<\/span>\necho<\/span>($x % $y); \/\/ 0utputs: 2<\/span>\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
PHP Assignment Operators<\/h2>\n\n\n\n
 The assignment operators are used to assign values to variables. <\/p>\n\n\n\n
Operator<\/th>Description<\/th>Example<\/th>Is The Same As<\/th><\/tr>
=<\/code><\/td>Assign<\/td>$x = $y<\/code><\/td>$x = $y<\/code><\/td><\/tr>
+=<\/code><\/td>Add and assign<\/td>$x += $y<\/code><\/td>$x = $x + $y<\/code><\/td><\/tr>
-=<\/code><\/td>Subtract and assign<\/td>$x -= $y<\/code><\/td>$x = $x - $y<\/code><\/td><\/tr>
*=<\/code><\/td>Multiply and assign<\/td>$x *= $y<\/code><\/td>$x = $x * $y<\/code><\/td><\/tr>
\/=<\/code><\/td>Divide and assign quotient<\/td>$x \/= $y<\/code><\/td>$x = $x \/ $y<\/code><\/td><\/tr>
%=<\/code><\/td>Divide and assign modulus<\/td>$x %= $y<\/code><\/td>$x = $x % $y<\/code><\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
\n\nThe following example will show you these assignment operators in action:\n\n<\/p>\n\n\n
<?php<\/span>\n$x = 10<\/span>;\necho<\/span> $x; \/\/ Outputs: 10<\/span>\n \n$x = 20<\/span>;\n$x += 30<\/span>;\necho<\/span> $x; \/\/ Outputs: 50<\/span>\n \n$x = 50<\/span>;\n$x -= 20<\/span>;\necho<\/span> $x; \/\/ Outputs: 30<\/span>\n \n$x = 5<\/span>;\n$x *= 25<\/span>;\necho<\/span> $x; \/\/ Outputs: 125<\/span>\n \n$x = 50<\/span>;\n$x \/= 10<\/span>;\necho<\/span> $x; \/\/ Outputs: 5<\/span>\n \n$x = 100<\/span>;\n$x %= 15<\/span>;\necho<\/span> $x; \/\/ Outputs: 10<\/span>\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
PHP Comparison Operators<\/h2>\n\n\n\n
 The comparison operators are used to compare two values in a Boolean fashion. <\/p>\n\n\n\n
Operator<\/th>Name<\/th>Example<\/th>Result<\/th><\/tr>
==<\/code><\/td>Equal<\/td>$x == $y<\/code><\/td>True if $x is equal to $y<\/td><\/tr>
===<\/code><\/td>Identical<\/td>$x === $y<\/code><\/td>True if $x is equal to $y, and they are of the same type<\/td><\/tr>
!=<\/code><\/td>Not equal<\/td>$x != $y<\/code><\/td>True if $x is not equal to $y<\/td><\/tr>
<><\/code><\/td>Not equal<\/td>$x <> $y<\/code><\/td>True if $x is not equal to $y<\/td><\/tr>
!==<\/code><\/td>Not identical<\/td>$x !== $y<\/code><\/td>True if $x is not equal to $y, or they are not of the same type<\/td><\/tr>
<<\/code><\/td>Less than<\/td>$x < $y<\/code><\/td>True if $x is less than $y<\/td><\/tr>
><\/code><\/td>Greater than<\/td>$x > $y<\/code><\/td>True if $x is greater than $y<\/td><\/tr>
>=<\/code><\/td>Greater than or equal to<\/td>$x >= $y<\/code><\/td>True if $x is greater than or equal to $y<\/td><\/tr>
<=<\/code><\/td>Less than or equal to<\/td>$x <= $y<\/code><\/td>True if $x is less than or equal to $y<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
 The following example will show you these comparison operators in action: <\/p>\n\n\n
<?php<\/span>\n$x = 25<\/span>;\n$y = 35<\/span>;\n$z = \"25\"<\/span>;\nvar_dump($x == $z);  \/\/ Outputs: boolean true<\/span>\nvar_dump($x === $z); \/\/ Outputs: boolean false<\/span>\nvar_dump($x != $y);  \/\/ Outputs: boolean true<\/span>\nvar_dump($x !== $z); \/\/ Outputs: boolean true<\/span>\nvar_dump($x < $y);   \/\/ Outputs: boolean true<\/span>\nvar_dump($x > $y);   \/\/ Outputs: boolean false<\/span>\nvar_dump($x <= $y);  \/\/ Outputs: boolean true<\/span>\nvar_dump($x >= $y);  \/\/ Outputs: boolean false<\/span>\n?><\/span><\/span>\n<\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
PHP Incrementing and Decrementing Operators<\/h2>\n\n\n\n
The increment\/decrement operators are used to increment\/decrement a variable’s value.<\/p>\n\n\n\n
Operator<\/th>Name<\/th>Effect<\/th><\/tr>
++$x<\/code><\/td>Pre-increment<\/td>Increments $x by one, then returns $x<\/td><\/tr>
$x++<\/code><\/td>Post-increment<\/td>Returns $x, then increments $x by one<\/td><\/tr>
--$x<\/code><\/td>Pre-decrement<\/td>Decrements $x by one, then returns $x<\/td><\/tr>
$x--<\/code><\/td>Post-decrement<\/td>Returns $x, then decrements $x by one<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
The following example will show you these increment and decrement operators in action:<\/p>\n\n\n
<?php<\/span>\n$x = 10<\/span>;\necho<\/span> ++$x; \/\/ Outputs: 11<\/span>\necho<\/span> $x;   \/\/ Outputs: 11<\/span>\n \n$x = 10<\/span>;\necho<\/span> $x++; \/\/ Outputs: 10<\/span>\necho<\/span> $x;   \/\/ Outputs: 11<\/span>\n \n$x = 10<\/span>;\necho<\/span> --$x; \/\/ Outputs: 9<\/span>\necho<\/span> $x;   \/\/ Outputs: 9<\/span>\n \n$x = 10<\/span>;\necho<\/span> $x--; \/\/ Outputs: 10<\/span>\necho<\/span> $x;   \/\/ Outputs: 9<\/span>\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
PHP Logical Operators<\/h2>\n\n\n\n
The logical operators are typically used to combine conditional statements.<\/p>\n\n\n\n
Operator<\/th>Name<\/th>Example<\/th>Result<\/th><\/tr>
and<\/code><\/td>And<\/td>$x and $y<\/code><\/td>True if both $x and $y are true<\/td><\/tr>
or<\/code><\/td>Or<\/td>$x or $y<\/code><\/td>True if either $x or $y is true<\/td><\/tr>
xor<\/code><\/td>Xor<\/td>$x xor $y<\/code><\/td>True if either $x or $y is true, but not both<\/td><\/tr>
&&<\/code><\/td>And<\/td>$x && $y<\/code><\/td>True if both $x and $y are true<\/td><\/tr>
||<\/code><\/td>Or<\/td>$x || $y<\/code><\/td>True if either $$x or $y is true<\/td><\/tr>
!<\/code><\/td>Not<\/td>!$x<\/code><\/td>True if $x is not true<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
The following example will show you these logical operators in action:<\/p>\n\n\n
<?php<\/span>\n$year = 2014<\/span>;\n\/\/ Leap years are divisible by 400 or by 4 but not 100<\/span>\nif<\/span>(($year % 400<\/span> == 0<\/span>) || (($year % 100<\/span> != 0<\/span>) && ($year % 4<\/span> == 0<\/span>))){\n    echo<\/span> \"$year is a leap year.\"<\/span>;\n} else<\/span>{\n    echo<\/span> \"$year is not a leap year.\"<\/span>;\n}\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
PHP String Operators<\/h2>\n\n\n\n
There are two operators which are specifically designed for strings<\/a>.<\/p>\n\n\n\n
Operator<\/th>Description<\/th>Example<\/th>Result<\/th><\/tr>
.<\/code><\/td>Concatenation<\/td>$str1 . $str2<\/code><\/td>Concatenation of $str1 and $str2<\/td><\/tr>
.=<\/code><\/td>Concatenation assignment<\/td>$str1 .= $str2<\/code><\/td>Appends the $str2 to the $str1<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
The following example will show you these string operators in action:<\/p>\n\n\n
<?php<\/span>\n$x = \"Hello\"<\/span>;\n$y = \" World!\"<\/span>;\necho<\/span> $x . $y; \/\/ Outputs: Hello World!<\/span>\n \n$x .= $y;\necho<\/span> $x; \/\/ Outputs: Hello World!<\/span>\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
PHP Array Operators<\/h2>\n\n\n\n
The array operators are used to compare arrays:<\/p>\n\n\n\n
Operator<\/th>Name<\/th>Example<\/th>Result<\/th><\/tr>
+<\/code><\/td>Union<\/td>$x + $y<\/code><\/td>Union of $x and $y<\/td><\/tr>
==<\/code><\/td>Equality<\/td>$x == $y<\/code><\/td>True if $x and $y have the same key\/value pairs<\/td><\/tr>
===<\/code><\/td>Identity<\/td>$x === $y<\/code><\/td>True if $x and $y have the same key\/value pairs in the same order and of the same types<\/td><\/tr>
!=<\/code><\/td>Inequality<\/td>$x != $y<\/code><\/td>True if $x is not equal to $y<\/td><\/tr>
<><\/code><\/td>Inequality<\/td>$x <> $y<\/code><\/td>True if $x is not equal to $y<\/td><\/tr>
!==<\/code><\/td>Non-identity<\/td>$x !== $y<\/code><\/td>True if $x is not identical to $y<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
The following example will show you these array operators in action:<\/p>\n\n\n
<?php<\/span>\n$x = array<\/span>(\"a\"<\/span> => \"Red\"<\/span>, \"b\"<\/span> => \"Green\"<\/span>, \"c\"<\/span> => \"Blue\"<\/span>);\n$y = array<\/span>(\"u\"<\/span> => \"Yellow\"<\/span>, \"v\"<\/span> => \"Orange\"<\/span>, \"w\"<\/span> => \"Pink\"<\/span>);\n$z = $x + $y; \/\/ Union of $x and $y<\/span>\nvar_dump($z);\nvar_dump($x == $y);   \/\/ Outputs: boolean false<\/span>\nvar_dump($x === $y);  \/\/ Outputs: boolean false<\/span>\nvar_dump($x != $y);   \/\/ Outputs: boolean true<\/span>\nvar_dump($x <> $y);   \/\/ Outputs: boolean true<\/span>\nvar_dump($x !== $y);  \/\/ Outputs: boolean true<\/span>\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
 Control Structures .<\/h1>\n\n\n\n
 Control Structures  <\/p>\n\n\n\n
What is a control structure?<\/h3>\n\n\n\n
Code execution can be grouped into categories as shown below<\/p>\n\n\n\n
  • Sequential <\/strong>\u2013 this one involves executing all the codes in the order in which they have been written.<\/li>
  • Decision<\/strong> \u2013 this one involves making a choice given a number of options. The code executed depends on the value of the condition.<\/li><\/ul>\n\n\n\n
    A control structure is a block of code that decides the execution path of a program depending on the value of the set condition.<\/p>\n\n\n\n
    Let\u2019s now look at some of the control structures that PHP supports.<\/p>\n\n\n\n
    PHP IF Else<\/h2>\n\n\n\n
    If\u2026 then… else is the simplest<\/strong>control<\/strong>structure<\/strong>. It evaluates the conditions using Boolean logic
    When to use if\u2026 then\u2026 else<\/strong>
    <\/p>\n\n\n\n
    • You have a block of code that should be executed only if a certain condition is true<\/li>
    • You have two options, and you have to select one.<\/li>
    • If\u2026 then\u2026 else if\u2026 is used when you have to select more than two options and you have to select one or more<\/li><\/ul>\n\n\n\n
      Syntax<\/strong> The syntax for if\u2026 then\u2026 else is;<\/p>\n\n\n
      <?php<\/span>\nif<\/span> (condition is true<\/span>) {\n\nblock one\n\nelse<\/span>\n\nblock two\n\n}\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
       HERE,<\/strong><\/p>\n\n\n\n
      • \u201cif (condition is true)\u201d<\/strong> is the control structure<\/li>
      • \u201cblock one<\/strong>\u201d is the code to be executed if the condition is true<\/li>
      • {\u2026else\u2026} <\/strong>is the fallback if the condition is false<\/li>
      • \u201cblock two<\/strong>\u201d is the block of code executed if the condition is false<\/li><\/ul>\n\n\n\n
        How it works<\/strong> The flow chart shown below illustrates how the if then\u2026 else control structure works<\/p>\n\n\n\n
        \"\"<\/figure>\n\n\n\n
        Let\u2019s see this in action<\/strong> The code below uses \u201cif\u2026 then\u2026 else\u201d to determine the larger value between two numbers. <\/p>\n\n\n
        <?php<\/span>\n\n$first_number = 7<\/span>;\n\n$second_number = 21<\/span>;\n\nif<\/span> ($first_number > $second_number){\n\necho<\/span> \"$first_number is greater than $second_number\"<\/span>;\n\n}else<\/span>{\n\necho<\/span> \"$second_number is greater than $first_number\"<\/span>;\n\n}\n\n?><\/span><\/span><\/code><\/span>Code language:<\/span> HTML, XML<\/span> (<\/span>xml<\/span>)<\/span><\/small><\/pre>\n\n\n
        Output:<\/strong><\/p>\n\n\n\n
        21 is greater than 7<\/pre>\n\n\n