只需将字符串传递给以下方法:

+(BOOL)isEmpty:(NSString *)str
{
    if(str.length==0 || [str isKindOfClass:[NSNull class]] || [str isEqualToString:@""]||[str  isEqualToString:NULL]||[str isEqualToString:@"(null)"]||str==nil || [str isEqualToString:@"<null>"]){
        return YES;
    }
    return NO;
}

看看这个:

if ([yourString isEqualToString:@""])
{
    NsLog(@"Blank String");
}

Or

if ([yourString length] == 0)
{
    NsLog(@"Blank String");
}

希望这能有所帮助。

这对我来说是一种魅力

如果NSString是s

if ([s isKindOfClass:[NSNull class]] || s == nil || [s isEqualToString:@""]) {

    NSLog(@"s is empty");

} else {

    NSLog(@"s containing %@", s);

}

在任何情况下，最好的方法是检查给定字符串的长度。如果你的字符串是myString，那么代码是:

    int len = [myString length];
    if(len == 0){
       NSLog(@"String is empty");
    }
    else{
      NSLog(@"String is : %@", myString);
    }

if(str.length == 0 || [str isKindOfClass: [NSNull class]]){
    NSLog(@"String is empty");
}
else{
    NSLog(@"String is not empty");
}    

另一个选项是用isEqualToString检查它是否等于@"":如下所示:

if ([myString isEqualToString:@""]) {
    NSLog(@"myString IS empty!");
} else {
    NSLog(@"myString IS NOT empty, it is: %@", myString);
}