iOS开发中判断空字符串的几种方法

 1 ios 判断字符串为空和只为空格解决办法 
 2 
 3 + (BOOL)isBlankString:(NSString *)string{ 
 4 
 5 if (string == nil) { 
 6 
 7 returnYES; 
 8 
 9 } 
10 
11 if (string == NULL) { 
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13 returnYES; 
14 
15 } 
16 
17 if ([string isKindOfClass:[NSNullclass]]) { 
18 
19 returnYES; 
20 
21 } 
22 
23 if ([[string stringByTrimmingCharactersInSet:[NSCharacterSetwhitespaceAndNewlineCharacterSet]] length]==0) { 
24 
25 returnYES; 
26 
27 } 
28 
29 returnNO; 
30 
31 }