End to Linear Programs! The most basic principle of any program is "what happens if ...". The condition can be written as a logical statement that can be valid (the condition is met) or not valid (then it is not executed or its exact opposite is performed). Both are easy to define.
Generally, a condition can be written as a logical statement. The condition may be met or not. It is good to count both variants as possible. If there are multiple alternatives, this is called a nested condition.
Example:
if (operation value ) {
// This is triggered if the condition is true
} else {
// This is triggered if the condition does not apply
}
We do not always have to define both variants (sometimes it is completely unnecessary). We can define the situation if only the condition applies. This is done as follows:
if (operation value) {
// This is triggered if the condition is true
}
| Operator | Meaning |
|---|---|
== | Equals |
=== | Equals and has the same data type (anything can be compared to anything, but the condition is met only if it is a value of the same data type (for example number, text,)) |
!= | Does not equal |
<= | Equals or is greater |
>= | Equals or less |
< | Greater |
> | Less |
$a = 5;
$b = 3;
if ($a === $b) {
// block to be printed if $a equals $b
} else {
// block to be printed if $a is NOT equal to $b
}
Unfortunately, the output is only true and false. So if we want to consider more options, we have to put more conditions into each other. This is called a nested condition. It is nested because one condition solution is another condition.
$a = 5; // left pocket
$b = 3; // right pocket
$pocket = true; // do I have a pocket?
if ($pocket === true) {
if ($a > $b) {
echo 'There's more in the left pocket';
} else {
echo 'There is more in the right pocket';
}
} else {
echo 'You have no pocket';
}