Hi I'm Learning php and trying to do a for loop look like this wtih this code:
for($x=1; $x<=20; $x++){
echo $x;
$x = $x + 3; //5
echo "<br/>";
}
It's produce
1
5
9
13
14
But I want it should be...
1
5
10
15
20
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4 Answers
for ($x = 0; $x <= 20; $x += 5) {
echo ($x == 0 ? 1 : $x), '<br>';
}
Or:
foreach (range(0, 20, 5) as $x) {
echo ($x == 0 ? 1 : $x), '<br>';
}
You can't produce the sequence without 1 extra condition because the delta differs in the first step:
1 + 4 ...
5 + 5
10 + 5
15 + 5
20 + 5
there are more than one solution.
one is:
for($x=1; $x<=20; $x++){
if(!($x % 5) || $x==1)
echo $x . "<br />";
}
Explination
% is the modulo operator. It returns the devision rest.
lets say $x is 3 than 3 % 5 would return 3 because the result 3/5 = 0 rest 3
if its $x is 10, it return 0. 10/5 = 2 rest 0
In the if-statement I use !-not operator. This turns around the result.
Because if takes 1+ (one and more) as true and 0- (zero and less) as false
So rest of 3 would be positiv (true) but in this case i want it to be false. So I turn arount the true/false with !
% - Modulo
R - Rest
1 % 5 = 0 R 1 // would say true to if
2 % 5 = 0 R 2 // would say true to if
3 % 5 = 0 R 3 // would say true to if
4 % 5 = 0 R 4 // would say true to if
5 % 5 = 1 R 0 // would say false to if
6 % 5 = 1 R 1 // would say true to if
and so on...
3 Comments
Lion King
@Shibbir: I don't know how did you accept this answer and you don't understand it
Dwza
@LionKing because it works and its tiny. I bet there are many thing in life you do, even if you don't know what really happens. May you drive a care whithout knowing what material the gas made out...
try this.
$x = 1;
for ($j = 1; $j <= 20; $j++) {
echo $x, "<br/>";
if ($x == 1) {
$x = $x + 4;
} else {
$x = $x + 5;
if($x > 20){break;}
}
}
if this answer is work for you please mark the answer.
1 Comment
Shibbir
I want to stop it to 20.
Try this:
for($x=1; $x<=20; $x++) {
if($x%5==0 || $x==1) {
echo $x;
echo "<br>";
}
}
