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iOS Swift 2.0 Collections and Control Flow Control Flow With Conditional Statements Working with Logical Operators

villa
villa
6,171 Points
Posted by villa
villa
6,171 Points

I need help no not get it

For this challenge, we'd like to know in a range of values from 1 to 100, how many numbers are both odd, and a multiple of 7.

To start us off, I've written a for loop to iterate over the desired range of values and named the local constant n. Your job is to write an if statement inside the for loop to carry out the desired checks.

If the number is indeed both an odd number and a multiple of 7, append the value to the results array provided.

Hint: To check for an odd number you can either use the remainder operator and 3, or use the not operator to check for "not even"

2 Answers

ianhan3
ianhan3
4,263 Points
  • Create an if else statement inside the loop that checks for two criteria: odd and multiple of 7.

Since we know every even value will be divisible by 2 evenly (no remainder) we can use the modulo operator to find odd (n % 2 != 0). Multiple of 7 is the same logic, just with 7 (n % 7 == 0).

if n % 2  != 0 && n % 7 == 0 {
    }
    else {
//generally you'll want to do something else with the other values but in the challenge, it doesn't matter.
    }
  • We then want to append the answers to the results array (provided). Super simple dot notation. Call the results array and append the temporary constant "n"
if n % 2  != 0 && n % 7 == 0 {
results.append(n)
    }
    else {
    }
ianhan3
ianhan3
4,263 Points

So all in all the final code will look like this (tested and passed):

var results: [Int] = []

for n in 1...100 {
    // Enter your code below
    if n % 2  != 0 && n % 7 == 0 {
results.append(n)
    }
    else {
    }
    // End code 
}

In plain english, the for loop takes every number in the specified range of 1 to 100 (1...100) and assigns it to a temporary constant, "n", while it executes the code inside the loop. Your code inside the loop evaluates each number by saying, "If when I take this number "n", divide it by two, will I get a remainder of 0?" If yes, move on to the else statement. If no (n % 2 != 0), check to see if the number, when divided by 7, has a remainder of 0. If yes, then execute the code inside the if {} which just tells it to add it to the empty array ("results") above.

villa
villa
6,171 Points
villa
villa
6,171 Points

thanks for your help, I understand better now.