- An operator is a special symbol that tells the compiler to perform some task.
PHP offers various operators to perform different tasks.
We can divide them into the following categories based on their operations.
- Arithmetic Operators
- Assignment Operators
- Incrementing/Decrementing Operators
- Relational Operators
- Logical Operators
- Array Operators
- Concatenate operator
Arithmetic operators are used to perform arithmetic tasks such as addition, subtraction, division etc. Main operators in this category are as follow:
|x + y||Addition||Sum of x and y||2 + 2||4|
|x – y||Subtraction||Difference of x and y||5 – 2||3|
|x * y||Multiplication||Product of x and y||5 * 2||10|
|x / y||Division||Quotient of x and y||15 / 5||3|
|x % y||Modulus||Remainder of x divided by y||5 % 2
10 % 8
10 % 2
|– x||Negation||Opposite of x||– 2|
|a . b||Concatenation||Concatenate two strings||“Hi” . “Ha”||HiHa|
- Assignment operator is used to assign righ hand side value to left hand side variable.
- In PHP “=” is used as assignment operator. It means that the left operand gets the value of the expression on the right hand side.
- For example the following code will assign the value 10 to variable x
$x = 10 ;
- Some various forms of assignment are as follow:
|x = y||x = y||The left operand gets set to the value of the expression on the right|
|x += y||x = x + y||Addition|
|x -= y||x = x – y||Subtraction|
|x *= y||x = x * y||Multiplication|
|x /= y||x = x / y||Division|
|x %= y||x = x % y||Modulus|
- Increment and decrement operator adds and subtracts to and from the current value by 1 respectively.
- Basic increment and decrement operators are “++” and “ –“.
- It has two forms: prefix and postfix.
|++ x||Prefix||Increments x by one, then returns x|
|x ++||Postfix||Returns x, then increments x by one|
|— x||Prefix||Decrements x by one, then returns x|
|x —||Postfix||Returns x, then decrements x by one|
- Relational operators are used to compare two values.
- Some examples are as follow:
|x == y||Equal||True if x is equal to y||5==8 returns false|
|x === y||Identical||True if x is equal to y, and they are of same type||5===”5″ returns false|
|x != y||Not equal||True if x is not equal to y||5!=8 returns true|
|x <> y||Not equal||True if x is not equal to y||5<>8 returns true|
|x !== y||Not identical||True if x is not equal to y, or they are not of same type||5!==”5″ returns true|
|x > y||Greater than||True if x is greater than y||5>8 returns false|
|x < y||Less than||True if x is less than y||5<8 returns true|
|x >= y||Greater than or equal to||True if x is greater than or equal to y||5>=8 returns false|
|x <= y||Less than or equal to||True if x is less than or equal to y||5<=8 returns true|
- Logical operators are used to perform logical task.
|x and y||And||True if both x and y are true||x=6
(x < 10 and y > 1) returns true
|x or y||Or||True if either or both x and y are true||x=6
(x==6 or y==5) returns true
|x xor y||Xor||True if either x or y is true, but not both||x=6
(x==6 xor y==3) returns false
|x && y||And||True if both x and y are true||x=6
(x < 10 && y > 1) returns true
|x || y||Or||True if either or both x and y are true||x=6
(x==5 || y==5) returns false
|! x||Not||True if x is not true||x=6
!(x==y) returns true
- Array operators are used to manipulate and perform different operations on array such as joining, equality check etc.
- Some examples are as follow:
|x + y||Union||Union of x and y|
|x == y||Equality||True if x and y have the same key/value pairs|
|x === y||Identity||True if x and y have the same key/value pairs in the same order and of the same types|
|x != y||Inequality||True if x is not equal to y|
|x <> y||Inequality||True if x is not equal to y|
|x !== y||Non-identity||True if x is not identical to y|
In PHP we can use period (“.”) operator as a concatenate operator to join two strings.
$str1 = "Hello" ; $str2 = "Welcome!" ; echo $str2 . $str1 ;
- The above code will display “Hello Welcome!” by joining two strings str1 and str2.