Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

iOS Swift Basics (retired) Control Flow If Statement

Frances Angulo
Frances Angulo
5,311 Points
Posted by Frances Angulo
Frances Angulo
5,311 Points

Else If vs. Just plain old If

Why does the teacher use else if when if seemed to work okay?

Teacher's example: 

for card in cards {
    if card == 11 {
        println("Jack")
    }else if card == 12 {
        println("Queen")
    } else {
        println(card)
    }
}

My example seemed to return the same results: 

for card in cards {
    if card == 11 {
        println("Jack")
    }; if card == 12 {
        println("Queen")
    } else {
        println(card)
    }
}

3 Answers

Fahad Alrahbi
Fahad Alrahbi
1,080 Points

Hello , your question is for programming concept as well ,

if you write

 if card == 11 {
        println("Jack")
    }else if card == 12 {
        println("Queen")
    } else {
        println(card)
    }

tha's mean if the first condition is true , compiler will skip other conditions as well , if the first condition is false the compiler will go to first else and will check if true so will skip other else as well ,

in other hand if you write 

if card == 11 {
        println("Jack")
    }; 

if card == 12 {
        println("Queen")
    } else {
        println(card)
    }

thats mean the compiler will check the first condition and at same time will check the if card ==12 because they are in different scope or block .

finally if you have different case and you want if one of different is true you use if else , otherwise you can use single if .

Frances Angulo
Frances Angulo
5,311 Points
Frances Angulo
Frances Angulo
5,311 Points

But the Assistant editor returned the same results - should it not have?

Fahad Alrahbi
Fahad Alrahbi
1,080 Points
Fahad Alrahbi
Fahad Alrahbi
1,080 Points

it should be there is some different and you will notice this different in case

This is my example 

var x = 10

if(x==10){
// Display 10 
let x=12
}else if (x==12){

// display 12 
}


if (x==10){
//display 10
let x=12 
}

if(x==12){
//display 12
}

i think now it's clear , in first example if will only display 10 , because the first condition is true , and it will skip the other if ,

in other ,

it will display 10 and 12

Note , I'm not writing by using any programming language , so you can convert my code to any language and check .

hope that was clear .

Samuel Seidel
Samuel Seidel
1,481 Points
Samuel Seidel
Samuel Seidel
1,481 Points

It's basically just saving processing time.