Comparing a string from the web

问题

hey all, i'm trying to read a file on the web that says "this is a test" and i wanna compare it... so here's what i got:

NSError *error;
NSURL *theURL = [NSURL URLWithString:@"http://mysite.com/test.asp"];
NSString *test = [NSString stringWithContentsOfURL:theURL encoding:NSASCIIStringEncoding error:&error];

NSLog(@"%@",test); //prints the results.. .does work


if(test == "this is a test"){
    NSLog(@"File read");
} else {
    NSLog(@"Bad file");
}

What am i doing wrong here? I always get "Bad file" but i know it's pulling in the text. Thanks all

damien

回答1:

You need to check for nil as well & use isEqualToString function for comparison.

if(test != nil){

    if([test isEqualToString:@"this is a test"]) {
       // equal
    }
    else{
      // not equal
    }
}

else{

   NSLog(@"Bad file");

}

回答2:

If you use ==, you'll be comparing two pointers. Use isEqual: like so:

if([test isEqual: @"this is a test"]) {
    // equal
}else{
    // not equal
}

回答3:

Other than the 2 answer you can also use.

– caseInsensitiveCompare:
– localizedCaseInsensitiveCompare:
– compare:
– localizedCompare:
– compare:options:
– compare:options:range:
– compare:options:range:locale:
– localizedStandardCompare:

来源：https://stackoverflow.com/questions/5201159/comparing-a-string-from-the-web