This code works, Just wondering how viable the if/else is inside of the for in loop. Is there a reason not to do this?

Question

for(i=0; i<students.length; i+= 1)
{

    for(var prop in students[i]){
      if(prop === "Name"){
       print("<p><strong>Student: " + students[i].Name + "</strong></p>"); 
      } else{
     print("<p>" + prop + ": " + students[i][prop] + "</p>"); 
      }
    }
}

Like i said in the question, when i test this along with my students array, it works fine. But i was wondering if any problem could arouse when using an if/else within a for in.

Answer 1 · 2015-09-14T23:16:26Z

September 14, 2015 11:16pm

Hi Dylan,

What you are doing is completely normal, and it's good you are being aware of this, as it can eventually become unmaintainable and inefficient to nest multiple times, but you have only nested once. I think what you are asking is, "Is this acceptable code, or is there a better way to do it?"

Generally, the first thing you want to do is get it to work. That is always the top priority. After that you might choose to do some refactoring to either make the code more maintainable and readable or to optimize for speed. If you're lucky you'll get both. The only thing I might do here is call a function in your loop to make it more readable. I don't see a need to filter since it appears you want to do something for each item in the array. Most of the built in array methods just call a for loop for you anyway underneath the hood. If you are interested in optimizing you will like jsperf. Not much has changed here, but a quick example:

var seth
  , students

seth = {
    Name: "Seth",
    Status: "average-joe",
    Work: "New Relic"   
}

students = [seth]

function logStudents () {
    for ( var prop in students[i] ) {
      if ( prop == "Name" ) console.log( "<p><strong>Student: " + students[i].Name + "</strong></p>" )
      else console.log( "<p>" + prop + ": " + students[i][prop] + "</p>" ) 
    }
}


for ( var i = 0; i < students.length; i++) {
    logStudents()
}

Hope this was helpful!

Cheers.

Answer 2 · 2015-09-14T22:20:45Z

September 14, 2015 10:20pm

What do you mean by 'viable'? I think it's pretty common to loop through an array and use a conditional statement to find something specific. It would probably be cleaner to use array.indexOf() or array.filter().

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Dylan Ryan

Dylan Ryan

This code works, Just wondering how viable the if/else is inside of the for in loop. Is there a reason not to do this?

2 Answers

Seth Shober

Seth Shober

Nathan Brenner

Nathan Brenner