6th December 2015
In
PHP
PHP Operators and conditional tests and events
By the end of this pots you should be able to:
- Identify and apply logical, arithmetic and relational operators to scripts
- Apply an assignment operator
What are operators?
Operators are symbols that transform the value of a variable or form comparisons against them.
Here are some examples of arithmetic operators:
$a = 42; $b = 20; $c = $a + $b; echo "Addition Operation Result: $c
"; $c = $a - $b; echo "Substraction Operation Result: $c
"; $c = $a * $b; echo "Multiplication Operation Result: $c
"; $c = $a / $b; echo "Division Operation Result: $c
"; $c = $a % $b; echo "Modulus Operation Result: $c
"; $c = $a++; echo "Increment Operation Result: $c
"; $c = $a--; echo "Decrement Operation Result: $c
";
Source: php.net/manual/en/language.operators.arithmetic.php
Logical Operators
//Test one: If both have something in them the condition will be TRUE - else FALSE $a = 40; $b = 1; if( $a && $b ){ echo "TEST1 : Both a and b are true
"; }else{ echo "TEST1 : Either a or b is false
"; } //Here we are using the 'and' operator if( $a and $b ){ echo "TEST2 : Both a and b are true
"; }else{ echo "TEST2 : Either a or b is false
"; }
Source: php.net/manual/en/language.operators.logical.php
Note: the use of:
&&
and
and
. Both are valid though && is supposed carry more precedence. I suggest && is the preferred choice.
Comparison or Relational Operators
Comparison operators are similar to logic but this is about comparing values against one another rather than simply on/off.
$a = 10; $b = 20; /*Ternary operators are if/else statements in shorthand*/ /* If condition is true then assign a to result otheriwise b */ $result = ($a > $b ) ? $a : $b; echo "TEST1 : Value of result is $result
"; /* If condition is true then assign a to result otheriwise b */ $result = ($a < $b ) ? $a : $b; echo "TEST2 : Value of result is $result
"; /* most basic usage of ternary operators */ $var = 5; $var_is_greater_than_two = ($var > 2 ? true : false); // returns true /*TIP: when learning how to use ternary operators write them in if/else first*/
Assignment Operators
In brief…
- Assignment operators assign a value to a variable
- Similar to arithmetic variables such as ++ or –
- They hold a variable with a value in memory and add additional value/s to it
- Assignment operators allow you to do complex calculations
- VAT and Non-VAT items for example
$a = 42; $b = 20; $c = $a + $b; /* Assignment operator */ echo "Addition Operation Result: $c
"; $c += $a; /* c value was 42 + 20 = 62 */ echo "Add AND Assigment Operation Result: $c
"; $c -= $a; /* c value was 42 + 20 + 42 = 104 */ echo "Subtract AND Assignment Operation Result: $c
"; $c *= $a; /* c value was 104 - 42 = 62 */ echo "Multiply AND Assignment Operation Result: $c
"; $c /= $a; /* c value was 62 * 42 = 2604 */ echo "Division AND Assignment Operation Result: $c
"; $c %= $a; /* c value was 2604/42 = 62*/ echo "Modulus AND Assignment Operation Result: $c
";
Source: php.net/manual/en/language.operators.assignment.php
In this post we have explored…
- Identified and applied logical, arithmetic and relational operators to scripts
- Applied assignment operators and discussed where we might apply them
No Comments