【IOS】判断字符串为空和只为空格解决办法

 1 + (BOOL)isBlankString:(NSString *)string
 2 {
 3     if (string == nil)
 4     {
 5         returnYES;
 6     }
 7     if (string == NULL)
 8     {
 9         returnYES;
10     }
11     if ([string isKindOfClass:[NSNullclass]])
12     {
13         returnYES;
14     }
15     if ([[string stringByTrimmingCharactersInSet:[NSCharacterSetwhitespaceAndNewlineCharacterSet]] length]==0)
16     {
17         returnYES;
18     }
19     returnNO;
20 }
21
22
23
24 +(Boolean) isEmptyOrNull:(NSString *) str
25 {
26
27     if (!str)
28     {
29
30         // null object
31
32         return YES;
33
34     }
35     else
36     {
37
38         NSString *trimedString = [str stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
39
40         if ([trimedString length] == 0)
41         {
42
43             // empty string
44
45             return YES;
46
47         }
48         else
49         {
50
51             // is neither empty nor null
52
53             return NO;
54
55         }
56
57     }
58 }