1 NSString *str;
2 // 使用stringWithFormat生成一格式化字符串
3 str = [NSString stringWithFormat:@"This is %@","John"];
4 NSLog(@"str--->%@",str);
5 // 字符串长度length;
6 NSLog(@"The length of this string is %@",[str length]);
7 // 字符串比较 isEqualToString, 返回NO(false)，isEqualToString区分大小写
8 BOOL isequal = [str isEqualToString:@"this is John"];
9
10 // 字符串序列比列 compare,返回结果NSComparisonResult
11 // type enum _NSComparisonResult{
12 // NSOrderedAscending = -1,
13 // NSOrderedSame,
14 // NSOrderedDescending
15 // }
16 int result = [@"bool" compare:@"cool"];
17 NSLog(@"The result is %d",result);
18
19 // compare 比较规则options
20 // NSLiteralSearch 区分大小写(完全比较)
21 // NSCaseInsensitiveSearch 不区分大小写
22 // NSNumericSearch 只比较字符串的个数，而不比较字符串的字面值
23 int result1 = [@"This is John" compare:@"this is John" options:NSCaseInsensitiveSearch | NSNumericSearch];
24 NSLog(@"The result is %d",result1);
25
26 // 字符串开头是否包括另一字符串 hasPrefix,返回结果YES(true)
27 BOOL isHas = [str hasPrefix:@"This"];
28 // 字符串结尾是否包括另一字符串 hasSuffix,返回结果YES(true)
29 BOOL isHas = [str hasSuffix:@"John"];
30
31 // 查找字符串在另一字符串中的位置
32 NSRange range = [str rangeOfString:@"is" options:NSCaseInsensitiveSearch];
33 NSLog(@"The location in the string named 'str' of 'is' is @d",range.location);
