index in a loop by using ..<

Question

I didn't understood the concept of the For-In loop in swift 3 , can anyone explain to us it m thanks in advance

var total = 0
for i in 0..<4 {
total += i
}
print(total)

The result of total is 6 , Why ?

Try putting a print statement in the loop and log the values of total and i at each iteration – that will show you what's happening. — Hamish
– Hamish, Commented May 18, 2017 at 9:31
I would also recommend having a read of the range operator section of the language guide. — Hamish
– Hamish, Commented May 18, 2017 at 9:37

Tristan · Accepted Answer · 2017-05-18 09:34:40Z

1

i=0 => total = 0+0 =0

i=1 => total = 0+1 = 1

i=2 => total = 1+2 = 3

i=3 => total = 3+3 =6

it's simply alogrithm ;-)

i never reach 4 because you said it STRICTLY inferior to 4 =)

(Do I answer your question?)

answered May 18, 2017 at 9:34

Tristan

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3 Comments

Thank you , but when i change it to 0..<5 it give 11 rather than 10 :/

You need to change 0...4 if you want to execute fro 0 to 4

@Tristan I made a mistake , i assumed the value of total as 1 , then all values are executed total +1

Ved Rauniyar · Accepted Answer · 2017-05-18 09:39:05Z

0

Your loop will be vary from 0 to 3 i.e. 0,1,2,3 but if you want it will vary from 0 to 4 then try this -

var total = 0
for i in 0...4 {
total += i
}
print(total)

answered May 18, 2017 at 9:39

Ved Rauniyar

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