# php Operators

Operators are one of the important feature of every language. # php Operators:

Operators are one of the important feature of every language. In php operators are classified in following categories:

 Name Symbol Example Output Addition + 2+2 4 Subtraction - 2-2 0 Division / 2/2 1 Multiplication * 2*2 4 Modulus % 2%2 0 Increment ++ let \$x=2 ++\$x 3 Decrement -- let \$y=5 --\$y 4 Negation - let \$a=2 -\$a -2

2. Comparison Operator

 Name Symbol Example Output is equal = = 2= =2 True is not equal != 2!=1 True is not equal <> 2!=2 False is greater than > 2>1 True is less than < 3<4 True is less than equal <= 2<=4 True is greater than equal >= 2>=4 False

3. Assignment Operator

 Name Symbol Example Output/Meaning assignment = \$x=2 assigns 2 into x combined operator (addition) += let \$x=2 \$x+=2 value of x will be 4 combined operator (subtraction) -= let \$x=2 \$x-=2 value of x will be 0 combined operator (multiplication) *= let \$x=3 \$x*=2 value of x will be 6 combined operator (division) /= let \$x=2 \$x/=2 value of x will be 1 combined operator (modulus) %= let \$x=2 \$x%=2 value of x will be 0

4. Logical Operator

 Name Symbol Example Output/Meaning And and \$x and \$y true if both are true Or or \$x or \$y true if at least one  is true Xor xor \$x xor \$y true if both equal, false if both unequal Not ! ! \$a returns true if variable is false, and vice versa And && \$a && \$b true if both are true Or || \$a || \$b true if at least one variable is true

5.String Operator

 Name Symbol Example Output/Meaning Concatenation Operator . (Period symbol) let \$a="Hello", \$b="World" \$a.\$b HelloWorld Concatenating Assignment Operator .= let \$a="Hello", \$a.="World" HelloWorld

6. Bitwise Operator

 Name Symbol Example Output/Meaning And & let \$a=11 and \$b=5 \$a & \$b 1 Or (Inclusive Or) | let \$a=11 and \$b=5 \$a | \$b 15 Xor (Exclusive Or) ^ let \$a=11 and \$b=5 \$a ^ \$b 14 Not ~ let \$a=11 ~ \$a -12 Right shift >> let \$a=11 and \$b=2 \$a >> \$b 2 Left shift << let \$a=11 and \$b=2 \$a << \$b 44

7. Error Control Operator

 Name Symbol Example Output/Meaning Error control operator @ [email protected]\$array['name']; will not generate any error message if index 'name' is not present

8. Execution Operator

 Name Symbol Example Output/Meaning backticks `` `ls -l` this operator is used to execute shell commands, the output can be stored in a variable also.

9. Array Operators:

Let us consider the following arrays:

\$a=array("lang"=>"Java", "platform"=>"Cross");

\$b=array("lang"=>"php", "platform"=>"Cross", "Year"=>"1995");

 Name Symbol Example Output/Meaning Union + \$a + \$b Array ( [lang] => php [paradigm] => imperative [Year] => 1995 ) Equality = = \$a = = \$b (Since both are unequal, no output will be generated) Identity = = = \$a = = = \$b (Since both are unequal, no output will be generated) Inequality != \$a != \$b 1 (Since both are unequal) Inequality <> \$a <> \$b 1 (Since both are unequal) Non-identity != = \$a != = \$b 1 (Since both are unequal)

10. Type operators:

In this example let us consider the following case:

<?php

class First{}

class Second{}

\$a=new First();

print_r(\$a instanceof First);

print_r(\$a instanceof Second);

?>

 Name Symbol Example Output/Meaning instanceof instanceof AS ABOVE 1 (Since \$a is the instance of class First) and On the second line nothing will be generated as \$a is not the instance of class Second