NSString * string=@"2011-11-29 12-11-10";
1查找
NSRange range = [string rangeOfString:@"-"];
if (range.location == NSNotFound)
{
NSLog(@"str中没有找到-");
}else {
NSLog(@"搜索范围%@",NSStringFromRange(range));
}
NSLiteralSearch区分大小写(完全比较)
NSCaseInsensitiveSearch不区分大小写
NSNumericSearch只比较字符串的个数，而不比较字符串的字面值
从尾开始搜索:
range = [str rangeOfString:@"456" options:NSBackwardsSearch] ;
NSLog(@"从尾搜索的范围%@",NSStringFromRange(range));
ios8.0以后使用，也是判断是否包含某个字符串：
BOOL result = [@“123" containsString:@"2"];
2替换
string=[string stringByReplacingOccurrencesOfString:@"-"withString:@"/"];
NSLog(@"replaceStr=%@",string);
3截取
NSString*bStr = [string substringWithRange:NSMakeRange(loc,2)];
loc表示从第几个字符开始，2表示截取两个字符；
[str substringToIndex:n];
从首字符开始截取n个字符;
[string substringFromIndex:n];
从第n+1位开始截取,至字符串最后;
4拆分
NSString*string =@"11111111A22222222";
NSArray*array = [string componentsSeparatedByString:@"A"];//从字符A中分隔成2个元素的数组
NSLog(@"array:%@",array);
NSLog(@"array1 ==== %@",[array firstObject]);
NSLog(@"array2 ==== %@",[array lastObject]);
5.验证
NSString*str1 =@"http:www.baidu.com";
BOOL a = [str1 hasPrefix:@"http"];//是否是以http开头
BOOL b = [str1 hasSuffix:@"com"];//文件路径是否以com结尾
NSLog(@"a ===== %d ,b ==== %d",a,b);
6.改变字符串的大小写
NSString* str2 =@"beiJING";
NSString*da = [str2 uppercaseString];//转成大写
NSString*xiao = [str2 lowercaseString];//转成小写
NSString*shouDa = [str2 capitalizedString];//首字母大写，其余小写
NSLog(@"\n大写==%@\n小写=== %@\n首字母大写其余小写=== %@",da,xiao,shouDa);
7.编码，解码
编码
NSString*hStr =@"你好啊";
NSString*hString = [hStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(@"hString === %@",hString);
解码
NSString*str3 =@"\u5982\u4f55\u8054\u7cfb\u5ba2\u670d\u4eba\u5458\uff1f";
NSString*str5 = [str3stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];
NSLog(@"string ==== %@",str5);