iOS NSSting 关于字符串的查找、截取、拆分、替换、验证、改变大小写、编码解码等

1、查找

NSString*str = @"bfjfnnfkanfknf";

NSRange range = [str rangeOfString:@"111"];

if (range.location == NSNotFound)

{

      NSLog(@"str中没有找到111");

}else {

     NSLog(@"搜索范围%@",NSStringFromRange(range));

}

下面的方法在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、截取

NSString*bStr = [str substringWithRange:NSMakeRange(loc,2)];

loc表示从第几个字符开始，2表示截取两个字符；

从首字符开始截取n个字符:

[str substringToIndex:n];

从第n+1位开始截取,至字符串最后:

[str substringFromIndex:n];

3、拆分

NSString*string =@"面朝大海/春暖花开";

NSArray*array = [string componentsSeparatedByString:@"/"];//从字符/中分隔成2个元素的数组

NSLog(@"array1 ==== %@",[array firstObject]);

NSLog(@"array2 ==== %@",[array lastObject]);
打印结果：array1 = 面朝大海，array2 = 春暖花开

4.替换

NSString*str =@"12345678";

NSString*replacedStr = [str stringByReplacingOccurrencesOfString:@"345"withString:@"想要替换成的字符串"];

NSLog(@"replacedStr ==== %@", replacedStr);

打印结果:

replacedStr ==== 12想要替换成的字符串678

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);

打印结果:

a ===== 1 ,b ==== 1

6.转成数字

[str boolValue];

[str integerValue];

7.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);

打印结果:

大写==BEIJING

小写=== beijing

首字母大写其余小写=== Beijing

8.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);

打印结果:

hString === %E4%BD%A0%E5%A5%BD%E5%95%8A

string ====如何联系客服人员？