2 Tips to Clean Ugly if Statements

Conditional statements are the backbone of programming but lot of times business requirements can lead to create long nested and ugly if statements.
This post demonstrates some tips to clean those ugly situations.

#1 Complex condition expressions

Long and complex condition expressions are obvious an ugly situation

// weird 😣😣
if((temp === 0) || (temp > 0 && temp < 5 && gusts > 10) || (snowing)){
//code block
}

Solution create a separate function to return a boolean that represents the long condition

// better 😁😁
if(isColdOutside(temp, windGusts, snowing)){
//code block
}

function isColdOutside(temp, windGusts, snowing){
  if(temp === 0){
   return true
  }
  if(snowing){
   return true
  }
  if(temp > 0 && temp < 5 && windGusts > 10){
   return true
  }
  return false
}

#2 Ternary into ternary

This is another situation that is ugly and the human brain struggle to parse

// weird 😣😣
let temp = 6
let windGusts = 20
let isFreezingOutside = temp < 5 ? (windGusts > 15 ? true : false) : (snowing ? true : false)

Solution again here we can create smaller functions to make it cleaner

// better 😁😁
let temp = 6
let windGusts = 20

let isFreezingOutside = temp < 1 ? isSnowing(snowing) : isWindStrong(windGusts)

function isWindStrong(windGusts){
  if(windGusts > 15){
   return true
  }
return false
}

function isSnowing(snowing){
  if(snowing){
   return true
  }
return false
}

This was two quick tips to clean ugly if statements.

Thanks for reading 😎😎😎

twitter @petroskoulianos

Comments

[amiceli]

Another tips I use :

if (a === "test" || a === "foo") {}

Better I think :

if (["test","foo"].includes(a)){}

[Tirtha Guha]

For #1 Complex condition expressions
I would prefer writing the complex condition, as it is simpler than 3 if statements.

function isColdOutside(temp, gusts, snowing){
  return ((temp === 0) || (temp > 0 && temp < 5 && gusts > 10) || (snowing))
}