Published Book on Amazon
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All of IOT Starting with the Latest Raspberry Pi from Beginner to Advanced – Volume 1 |
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All of IOT Starting with the Latest Raspberry Pi from Beginner to Advanced – Volume 2 |
출판된 한글판 도서
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최신 라즈베리파이(Raspberry Pi)로 시작하는 사물인터넷(IOT)의 모든 것 – 초보에서 고급까지 (상) |
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최신 라즈베리파이(Raspberry Pi)로 시작하는 사물인터넷(IOT)의 모든 것 – 초보에서 고급까지 (하) |
Original Book Contents
24.4.4 Operation
There are a number of operations supported by PHP as follows:
■ Arithmetic operation
■ Assignment operation
■ Comparison operation
■ Incremental/ Decremental operation
■ Logical operation
■ String operation
■ Array operation
24.4.4.1 Arithmetic Operator
Arithmetic operator is operator that is used for general calculations by using numbers.
| Operator | Description & Same as… | Example | Result |
| + | Addition | $x + $y | Sum of $x and $y |
| - | Subtraction | $x - $y | Difference of $x and $y |
| * | Multiplication | $x * $y | Product of $x and $y |
| / | Division | $x / $y | Quotient of $x and $y |
| % | Modulus | $x % $y | Remainder of $x divided by $y |
| ** | Exponentiation | $x ** $y | Result of raising $x to the $y'th power |
24.4.4.2 Assignment Operator
An assignment operator is operator that you use to assign value to variable. In PHP, "=" operator is used. It specifies the result of expression on the right to the left operand.
When you want to specify a value to a specific key in array, "=>" operator is used.
| Operator | Description & Same as… | Example | Result |
| x = y | The left operand gets set to the value of the expression on the right. x = y | ||
| x += y | Addition. x = x + y | ||
| x -= y | Subtraction. x = x - y | ||
| x *= y | Multiplication. x = x * y | ||
| x /= y | Division. x = x / y | ||
| x %= y | Modulus. x = x % y |
[Used Example]
Next is an example of assignment operators
| <?php |
24.4.4.3 Comparison Operator
A comparison operator is an operator that compares values of two characters or numbers with each other.
| Operator | Description & Same as… | Example | Result |
| == | Equal | $x == $y | Returns true if $x is equal to $y |
| === | Identical | $x === $y | Returns true if $x is equal to $y, and they are of the same type |
| != | Not equal | $x != $y | Returns true if $x is not equal to $y |
| <> | Not equal | $x <> $y | Returns true if $x is not equal to $y |
| !== | Not identical | $x !== $y | Returns true if $x is not equal to $y, or they are not of the same type |
| > | Greater than | $x > $y | Returns true if $x is greater than $y |
| < | Less than | $x < $y | Returns true if $x is less than $y |
| >= | Greater than or equal to | $x >= $y | Returns true if $x is greater than or equal to $y |
| <= | Less than or equal to | $x <= $y | Returns true if $x is less than or equal to $y |
24.4.4.4 Incremental/Decremental Operator
An incremental operator increases the value of a variable by one, and a decremental operator decreases the value of a variable by one.
| Operator | Description & Same as… | Example | Result |
| ++$x | Pre-increment. Increments $x by one, then returns $x | ||
| $x++ | Post-increment. Returns $x, then increments $x by one | ||
| --$x | Pre-decrement. Decrements $x by one, then returns $x | ||
| $x-- | Post-decrement. Returns $x, then decrements $x by one |
24.4.4.5 Logical Operator
A logical operator is an operator that combines two conditional statements to create a new logical result..
| Operator | Description & Same as… | Example | Result |
| and | And | $x and $y | True if both $x and $y are true |
| or | Or | $x or $y | True if either $x or $y is true |
| xor | Xor | $x xor $y | True if either $x or $y is true, but not both |
| && | And | $x && $y | True if both $x and $y are true |
| || | Or | $x || $y | True if either $x or $y is true |
| ! | Not | !$x | True if $x is not true |
24.4.4.6 String Operator
A string operator is an operator that connects several strings together.
| Operator | Description & Same as… | Example | Result |
| . | Concatenation | $txt1 . $txt2 | Concatenation of $txt1 and $txt2 |
| .= | Concatenation assignment | $txt1 .= $txt2 | Appends $txt2 to $txt1 |
24.4.4.7 Array Operator
An array operator is an operator used when comparing arrays.
| Operator | Description & Same as… | Example | Result |
| + | Union | $x + $y | Union of $x and $y |
| == | Equality | $x == $y | Returns true if $x and $y have the same key/value pairs |
| === | Identity | $x === $y | Returns true if $x and $y have the same key/value pairs in the same order and of the same types |
| != | Inequality | $x != $y | Returns true if $x is not equal to $y |
| <> | Inequality | $x <> $y | Returns true if $x is not equal to $y |
| !== | Non-identity | $x !== $y | Returns true if $x is not identical to $y |