Swift - Variables and Constants
You want to store the number of days in a week as a constant in Swift. Which code correctly declares this and prevents accidental changes later?
You want to store the number of days in a week as a constant in Swift. Which code correctly declares this and prevents accidental changes later?
hard📝 Application Q15 of 15
Step-by-Step Solution
Solution:
Step 1: Choose correct keyword for constant
Usingletdeclares a constant that cannot be changed after assignment.Step 2: Check code correctness
let daysInWeek = 7 // daysInWeek cannot be changed laterdeclares and assignsdaysInWeekwith 7 and prevents changes later.var daysInWeek = 7 // Later changed to 8 accidentallyusesvarwhich allows changes.constant daysInWeek = 7 // Prevents changesuses invalid keyword.let daysInWeek // Assign value laterdeclares without assignment, which is invalid for constants.Final Answer:
let daysInWeek = 7 // daysInWeek cannot be changed later -> Option DQuick Check:
Use let with assignment to make constant = A [OK]
Quick Trick: Use let with immediate value to make constant [OK]
Common Mistakes:
- Using var instead of let for constants
- Trying to declare let without initial value
- Using non-Swift keywords like constant
Master "Variables and Constants" in Swift
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