Check for String within a String

I'm trying to compare two strings

NSString strOne = @"Cat, Dog, Cow";
NSString strTwo = @"Cow";

Ho开发者_运维技巧w do I determine if strOne contains strTwo

Try using rangeOfString:

NSRange result = [strOne rangeOfString:strTwo];

From the documentation:

Returns an NSRange structure giving the location and length in the receiver of the first occurrence of aString. Returns {NSNotFound, 0} if aString is not found or is empty (@"").

For anyone needing the code to check is a string exists within a string, here's my code thanks to fbrereto. This example checks to see if any string contained in an array of strings (stringArray) can be found within a string (myString):

int count = [stringArray count];

for (NSUInteger x = 0; x < count; ++x) {

    NSRange range = [self.myString rangeOfString:[stringArray objectAtIndex:x]];

    if (range.length > 0) {
        // A match has been found
        NSLog(@"string match: %@",[stringArray objectAtIndex:x]);
    }
}

I believe this is the correct syntax for checking if the range exists (correcting response from Kendall): range.location != NSNotFound

Gradually straying off topic, but I always explode my strings, which would mean just exploding it using your search string as a key and you can use the array count to see how many instances you have.

Just incase anyone is coming from a code language that uses "explode" to blow a string up into an array like me, I found writing my own explode function tremendously helpful, those not using "explode" are missing out:

- (NSMutableArray *) explodeString : (NSString *)myString key:(NSString*) myKey
{
    NSMutableArray *myArray = [[NSMutableArray alloc] init];
    NSRange nextBreak = [myString rangeOfString:myKey];
    while(nextBreak.location != NSNotFound)
    {
        [myArray addObject: [myString substringToIndex:nextBreak.location]];
        myString = [myString substringFromIndex:nextBreak.location + nextBreak.length];
        nextBreak = [myString rangeOfString:myKey];
    }
    if(myString.length > 0)
        [myArray addObject:myString];

    return myArray;
}

works like this:

[self explodeString: @"John Smith|Age: 37|Account Balance: $75.00" key:@"|"];

which will return this array:

[@"John Smith", @"Age: 37", @"Account Balance: $75.00"];

This lets you quickly pull out a specific value in a tight space, Like if you have a client and you want to know how much money he has:

[[self explodeString: clientData key: pipe] objectAtIndex: 1];

or if you wanted specifically the dollar amount as a float:

[[[self explodeString: [[self explodeString: clientData key: pipe] objectAtIndex: 1] key: @": "] objectAtIndex: 2] floatValue];

anyway I find arrays way easier to work with and more flexible, so this is very helpful to me. Additionally with a little effort you could make an "explodable string" data type for your private library that lets you treat it like a string or return an index value based on the key

ExplodableString *myExplodableString;
myExplodableString.string = @"This is an explodable|string";
NSString *secondValue = [myExplodableString useKey: @"|" toGetValue: index];