{"id":10880,"date":"2020-02-21T05:37:35","date_gmt":"2020-02-21T05:37:35","guid":{"rendered":"https:\/\/www.devopsschool.com\/blog\/?p=10880"},"modified":"2021-11-12T10:25:33","modified_gmt":"2021-11-12T10:25:33","slug":"logical-increment-decrement-and-string-operators-in-php","status":"publish","type":"post","link":"https:\/\/www.devopsschool.com\/blog\/logical-increment-decrement-and-string-operators-in-php\/","title":{"rendered":"Logical, Increment, decrement, and String Operators in PHP."},"content":{"rendered":"\n

Logical Operators<\/h1>\n\n\n\n

1. Logical AND(&&\/and).<\/h3>\n\n\n\n

There are two Logical AND Operators, First &&<\/strong><\/em> and 2nd and<\/em><\/strong> where First Operator has higher precedence(means higher priority) than 2nd. It Compares two expressions or operators and gives output in 4 cases. See the Below image.<\/em><\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

Case 1.<\/strong> When Both the expressions are true<\/em> then it returns True<\/em><\/strong>. <\/p>\n\n\n\n

For Example :- <\/strong> (5>2)&&(5<8) <\/em><\/p>\n\n\n\n

In the above Example, It returns True<\/em><\/strong> because both the expressions are true<\/em>.<\/p>\n\n\n\n

Case 2.<\/strong> When 1st expression is true <\/em>and 2nd is false <\/em>then it returns False<\/em><\/strong>. <\/p>\n\n\n\n

For Example :-<\/strong> (3<5)&&(5<2)<\/em><\/p>\n\n\n\n

In the above Example, 1st expression is true<\/em> but 2nd expression is false<\/em> then it returns False<\/em><\/strong>.<\/p>\n\n\n\n

Case 3.<\/strong> When 1st expression is false<\/em> and 2nd is true <\/em>then it returns False<\/em><\/strong>.<\/p>\n\n\n\n

For Example :-<\/strong> (5<2)&&(3<5)<\/em> <\/p>\n\n\n\n

In the above Example, 1st expression is false<\/em> but 2nd expression is true<\/em> then it returns False<\/em><\/strong>.<\/p>\n\n\n\n

Case 4.<\/strong> When Both the Expression is false<\/em> then it also returns False<\/strong><\/em>. <\/p>\n\n\n\n

For Example :-<\/strong> (6<2)&&(3>5)<\/em><\/p>\n\n\n\n

In the above Example, Both expressions are false<\/em> then it returns False<\/em><\/strong>. <\/p>\n\n\n\n

2. Logical OR(||<\/strong><\/em>\/or).<\/h3>\n\n\n\n

There are Two Logical OR, First ||<\/strong> and 2nd or<\/em><\/strong> where First Operator has higher precedence(means higher priority) than 2nd. It Compares two expressions or operators and gives output in 4 cases. See the Below image.<\/em> <\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Case 1.<\/strong> When Both the expressions are true<\/em> then it returns True<\/em><\/strong>. <\/p>\n\n\n\n

For Example :-<\/strong> (5>2)||<\/strong>(5<8)<\/em><\/p>\n\n\n\n

In the above Example, It returns True<\/em><\/strong> because both the expressions are true<\/em>.<\/p>\n\n\n\n

Case 2.<\/strong> When 1st expression is true <\/em>and 2nd is false <\/em>then it returns True<\/em><\/strong>. <\/p>\n\n\n\n

For Example :-<\/strong> (3<5)||<\/strong>(5<2)<\/em><\/p>\n\n\n\n

In the above Example, 1st expression is true<\/em> but 2nd expression is false<\/em> then it returns True<\/em><\/strong>.<\/p>\n\n\n\n

Case 3.<\/strong> When 1st expression is false<\/em> and 2nd is true <\/em>then it returns True<\/em><\/strong>. <\/p>\n\n\n\n

For Example :-<\/strong> (5<2)<\/em>||<\/strong>(3<5)<\/em> <\/p>\n\n\n\n

In the above Example, 1st expression is false<\/em> but 2nd expression is true<\/em> then it returns True<\/em><\/strong>.<\/p>\n\n\n\n

Case 4.<\/strong> When Both the Expression is false<\/em> then it also returns False<\/strong><\/em>. For <\/p>\n\n\n\n

Example :-<\/strong> (6<2)<\/em>||<\/strong>(3>5)<\/em><\/p>\n\n\n\n

In the above Example, Both expressions are false<\/em> then it returns False<\/em><\/strong>. <\/p>\n\n\n\n

3. Logical NOT(!).<\/h3>\n\n\n\n

It returns the reverse value of expression means when the expression is true<\/em> then it returns False<\/em><\/strong>, and when the expression is false<\/em> then it returns True.<\/em><\/strong> <\/p>\n\n\n\n

For Example :-<\/strong> !(3<2)<\/em><\/p>\n\n\n\n

In the above example, the expression is false<\/em> but it returns True<\/em><\/strong>. <\/p>\n\n\n\n

4. Exclusive OR(xor).<\/h3>\n\n\n\n

When both the expression are Identical (means both are true<\/em> or false<\/em>) then it returns False<\/em><\/strong> and when any one of them is true<\/em> then it returns True<\/em><\/strong>. See the below image.<\/em><\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

Case 1.<\/strong> When Both the expressions are true<\/em> or false<\/em> then it returns False<\/em><\/strong>. <\/p>\n\n\n\n

For Example :-<\/strong> (5>2)xor(5<8)<\/em> or (6<2)<\/em>||<\/strong>(3>5)<\/em> <\/p>\n\n\n\n

In the above example, both the expressions in the first example is true<\/em> and both the expressions in the second example is false<\/em> so both the examples return False<\/strong><\/em>. <\/p>\n\n\n\n

Case 2.<\/strong> When 1st expression is true <\/em>and 2nd is false <\/em>then it returns True<\/em><\/strong>. <\/p>\n\n\n\n

For Example :- <\/strong> (3<5)xor(5<2)<\/em><\/p>\n\n\n\n

In the above Example, 1st expression is true<\/em> but 2nd expression is false<\/em> then it returns True<\/em><\/strong>.<\/p>\n\n\n\n

Case 3.<\/strong> When 1st expression is false<\/em> and 2nd is true <\/em>then it returns True<\/em><\/strong>. <\/p>\n\n\n\n

For Example :-<\/strong> (5<2)xor(3<5)<\/em> <\/p>\n\n\n\n

In the above Example, 1st expression is false<\/em> but 2nd expression is true<\/em> then it returns True<\/em><\/strong>. <\/p>\n\n\n\n

Increment and Decrement Operators.<\/h1>\n\n\n\n

Increment Operator:- <\/em><\/strong> It increases the value of the variable by 1. It is of two types:<\/p>\n\n\n\n

1. Pre-increment:- <\/em><\/strong> It first increases the value of variable, then uses the new variable value. <\/p>\n\n\n\n

For Example:-<\/strong> ++$a<\/strong> <\/p>\n\n\n\n

<?php
$a=40;
echo ++$a;
?><\/em><\/p>\n\n\n\n

Output :-<\/strong> 41<\/p>\n\n\n\n

2. Post-increment:-<\/em><\/strong> First uses the current value of the variable, then increases the value of variable by 1.<\/p>\n\n\n\n

For Example:-<\/strong> $a++<\/strong><\/p>\n\n\n\n

<?php
$a=25;
echo $a++.”<br>”;
echo $a;
?><\/em><\/p>\n\n\n\n

Output:-<\/strong> 25
26 <\/p>\n\n\n\n

Decrement Operator:-<\/em><\/strong> It decreases the value of the variable by 1. It is of two types: <\/p>\n\n\n\n

1. Pre-decrement:- <\/em><\/strong> It first decreases the value of the variable, then uses the new variable value. <\/p>\n\n\n\n

For Example:-<\/strong> – – $a<\/strong> <\/p>\n\n\n\n

<?php
$a=40;
echo – – $a;
?><\/em><\/p>\n\n\n\n

Output :-<\/strong> 39<\/p>\n\n\n\n

2. Post-decrement:-<\/em><\/strong> First uses the current value of the variable, then decreases the value of the variable by 1.<\/p>\n\n\n\n

For Example:-<\/strong> $a- –<\/strong><\/p>\n\n\n\n

<?php
$a=25;
echo $a – -.”<br>”;
echo $a;
?><\/em><\/p>\n\n\n\n

Output:-<\/strong> 25
24 <\/p>\n\n\n