Using multiple else if statements for NSInteger - ios

Question

I have a section of code, in which I want a different accessoryView for the TableView cell, based off the number for that cell's entry. The code I have set up is:
NSInteger warriors = [entry.prayerWarriors intValue];
if (warriors == 0) {
//Do nothing
//NSLog(#"0");
}
else if (0 < warriors < 50) {
cell.accessoryView = firstLevel;
// NSLog(#"50");
}
else if (51 < warriors < 100) {
cell.accessoryView = secondLevel;
// NSLog(#"100");
}
else if (101 < warriors < 500) {
cell.accessoryView = thirdLevel;
// NSLog(#"500");
}
else {
cell.accessoryView = fourthLevel;
// NSLog(#"A Lot");
}
However, it always returns only the first entry for warriors == 0. What am I doing wrong?

Answer 1

Rather than doing this...
else if (0 < warriors < 50) {
cell.accessoryView = firstLevel;
// NSLog(#"50");
}
do this...
else if (0 < warriors && warriors < 50) {
cell.accessoryView = firstLevel;
// NSLog(#"50");
}
EDIT
To answer your comment...you probably mean to have some <= or >= in there, as it's going to the last else when warriors equals the border of your if conditionals (50, 100 or 500).
You probably want it to look like this...
NSInteger warriors = [entry.prayerWarriors intValue];
if (warriors == 0) {
//Do nothing
//NSLog(#"0");
}
else if (0 < warriors && warriors <= 50) {
cell.accessoryView = firstLevel;
// NSLog(#"50");
}
else if (50 < warriors && warriors <= 100) {
cell.accessoryView = secondLevel;
// NSLog(#"100");
}
else if (100 < warriors && warriors <= 500) {
cell.accessoryView = thirdLevel;
// NSLog(#"500");
}
else {
cell.accessoryView = fourthLevel;
// NSLog(#"A Lot");
}

Answer 2

The statement
if (0 < warriors < 50)
evaluates different than you might think. The first part
(0 < warriors)
evaluates as a boolean, and that boolean will be compared to 50.
So, you need to do: if (0 < warriors && warriors < 50)

Answer 3

The other answers make good points about the later cases needing a logical and but if you are getting stuck at if (warriors == 0) { most likely your object entry.prayerWarriors is nil. Put a break point and print it out. (and print out it's class to make sure its as expected)
Also minor but a good habit to be in your conversion of what I'm guessing is an NSNumber isn't using the same type as your variable. Since you are writing into a NSInteger you should replace intValue with integerValue

Answer 4

For clarity, I prefer to put the variable first in each condition and to encapsulate each part of the condition:
if (warriors == 0) {
//Do nothing
NSLog(#"0");
}
else if ((warriors > 0) && (warriors < 50))
{
cell.accessoryView = firstLevel;
NSLog(#"50");
}
else if ((warriors > 51) && (warriors < 100)) {
cell.accessoryView = secondLevel;
NSLog(#"100");
}
else if ((warriors > 101) && (warriors < 500)) {
cell.accessoryView = thirdLevel;
NSLog(#"500");
}
else {
cell.accessoryView = fourthLevel;
NSLog(#"A Lot");
}
Just be sure you've have enough parens around the conditions.

Answer 5

You do not need an if cascade for this:
You can store the levels one time anywhere
NSArray *levels = #[firstLevel, secondLevel, thirdLevel, fourthLevel];
And use it indexed:
if( warriors > 0) {
cell.accessoryView = levels[(warriors-1) / 50]
}
But if you want to have an if cascade, you do not have to double check:
NSInteger warriors = [entry.prayerWarriors intValue];
if (warriors == 0) {
//Do nothing
//NSLog(#"0");
}
else if (warriors <= 50) {
cell.accessoryView = firstLevel;
// NSLog(#"50");
}
else if (warriors <= 100) {
cell.accessoryView = secondLevel;
// NSLog(#"100");
}
else if (warriors <= 500) {
cell.accessoryView = thirdLevel;
// NSLog(#"500");
}
else {
cell.accessoryView = fourthLevel;
// NSLog(#"A Lot");
}
If you are in an else, it is already tested that the preceding condition failed.(That's the meaning of else.)