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Ben Os
20,008 Pointsphp: I have no idea why I get a "Unidentified variable" error here, plus an infinite loop...
I work locally with notepad++ on purpose so I didn't copy anything from the teacher so he might have preliminary code pieces that I miss, and thus can't get the following code to work:
for($counter = 0; $border = 10; $adder + 1){
echo "<li>" . $counter . "</li>";
}
4 Answers
Dale Severude
Full Stack JavaScript Techdegree Graduate 71,349 PointsI am not sure why you want to use a $adder variable or a $border variable. Using a single variable the loop should work fine.
for($counter = 0; $counter < 10; $counter++){
echo "<li>" . $counter . "</li>";
}
Dale Severude
Full Stack JavaScript Techdegree Graduate 71,349 PointsHi Ben, In the code you have shown, $adder is not defined anywhere, this is your unidentified variable. Also in your loop there is no conditional statement, which is what is causing an infinite loop.
Here is the traditional way of doing a For Loop:
for($counter = 0; $counter < 10; $counter++) {}
Ben Os
20,008 PointsHi, I tried to work with the traditional way but I got these errors thus I changed... Anyway indeed I want to work in this traditional way...
Can you detail about the $adder variable? Even when I defined it outside and did the following I still encounter the same problems:
$adder = 1;
for($counter = 0; $border < 10; $adder++){
echo "<li>" . $counter . "</li>";
}
Ben Os
20,008 PointsIndeed! It worked when I used a single variable as you you showed Dale! Thanks!
The reason I used three different variables was that after I saw the for loop is built using variables in php I used the terminology I knew from a Introduction to JS I had (there I didn't use variables I just this names in my mind for the three modular parts of the loop in JS but anyway, in PHP I'll work with one variable as you showed.
Since I am very very new to both languages (and to programming in general) I want to ask (hope it's okay), how come the php for loop knows how to treat each representation of the variable inside it? Is it built-in functionality of the php for loop?
Dale Severude
Full Stack JavaScript Techdegree Graduate 71,349 PointsThe loop has 3 parts. First is the variable declaration, second is the variable test condition, and third is the variable modifier. The first part initializes $counter to 0 and then is not used again. Then a loop begins which tests if $counter is less than 10, and if not, $counter is incremented by 1. The code in the brackets is executed each time through each increment. Finally when it hits 10, the condition fails, and it exits the loop. This is a common programming loop used in PHP, JavaScript, and probably any other programming language.