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Start your free trialKat Cuccia
786 PointsWhy does a variable assigned one double quote test as a false boolean value?
One of the questions in the final quiz asks, "Which of the following variables would be considered FALSE when tested as a boolean?" The correct answer is $name = ";
. Why on earth does a "
result in false??
2 Answers
andren
28,558 PointsBecause PHP (as well as many other languages) has certain values they consider "Truthy" and some which they consider "Falsy". As you might guess "Truthy" values are converted to the boolean true
and "Falsy" are converted to false
.
In the case of PHP there is a set list of values that are considered "Falsy", and any value that is not in that list are considered "truthy". Here is the list of "Falsy" values:
- The boolean FALSE itself
- The integer 0 (zero)
- The float 0.0 (zero)
- The empty string, and the string "0"
- An array with zero elements
- The special type NULL (including unset variables)
- SimpleXML objects created from empty tags
Since $name
is set to an empty string in the Quiz it is considered false
.
Cristian Opran
6,963 Pointsgood answer, thank you
Kat Cuccia
786 PointsKat Cuccia
786 PointsThank you!