编码样式 - 如何格式化long if条件以使其可读

Question

I have a long if condition as follows. There are two conditions that both have to not be met, for the statement to evaluate. I did have it as a one liner with a lot of && and ! but it became unreadable. I have tried splitting it into an if elsif else, which is more readable but doesn't read well, as the first if elsif blocks have no code in them.

What would be the best practice to tidy this code block?

if ($instructionObject->instruction=='nesting_grammar' && $instructionObject->match=='>'){ //if instruction is a '>' child indicator
   //don't change the child depth
}else if ($instructionObject->instruction=='selector' && is_object($this->instructions[$key+1]) && $this->instructions[$key+1]->instruction == 'nesting_grammar' && $this->instructions[$key+1]->match == '>'){ //if instruction is a selector followed by a '>'
   //don't change the child depth
}else{
   $insertOffset += $childDepth;
   unset($childDepth);
}

Answer 1

You can use "extract method" refactoring. Replace your conditions to new methods.

if ($this->isInstructionNestingGrammar($instructionObject)){ 
   //don't change the child depth
}else if ($this->isIntructionSelect($instructionObject)){ 
   //don't change the child depth
}else{
   $insertOffset += $childDepth;
   unset($childDepth);
}

In new methods put every compare to separate line.

P.S. Don't be afraid of long name of methods.