Parameters which have default values should be placed at the end.
If you place a parameter with a default value before a parameter with a default value,
the default value of the first parameter will never be used as it will always
need to be passed anyway:
// $a must always be passed; it's default value is never used.functionsomeFunction($a=5,$b){}
If you place a parameter with a default value before a parameter with a default value, the default value of the first parameter will never be used as it will always need to be passed anyway: