An if expression is missing an else block.
Erroneous code example:
let x = 5;
let a = if x == 5 {
1
};This error occurs when an if expression without an else block is used in a
context where a type other than () is expected. In the previous code example,
the let expression was expecting a value but since there was no else, no
value was returned.
An if expression without an else block has the type (), so this is a type
error. To resolve it, add an else block having the same type as the if
block.
So to fix the previous code example:
let x = 5;
let a = if x == 5 {
1
} else {
2
};