NSString * string=@"2011-11-29 12-11-10";

1查找

NSRange range = [string rangeOfString:@"-"];

if (range.location == NSNotFound)

{

? ? ? NSLog(@"str中沒有找到-");

}else {

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

}

NSLiteralSearch區(qū)分大小寫(完全比較)

NSCaseInsensitiveSearch不區(qū)分大小寫

NSNumericSearch只比較字符串的個(gè)數(shù)，而不比較字符串的字面值

從尾開始搜索:

range = [str rangeOfString:@"456" options:NSBackwardsSearch] ;

NSLog(@"從尾搜索的范圍%@",NSStringFromRange(range));

ios8.0以后使用，也是判斷是否包含某個(gè)字符串：

BOOL result = [@“123" containsString:@"2"];

2替換

? string=[string stringByReplacingOccurrencesOfString:@"-"withString:@"/"]; ? ? ? ?

NSLog(@"replaceStr=%@",string);

3截取

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

loc表示從第幾個(gè)字符開始，2表示截取兩個(gè)字符；

[str substringToIndex:n];

從首字符開始截取n個(gè)字符;

[string substringFromIndex:n];

從第n+1位開始截取,至字符串最后;

4拆分

NSString*string =@"11111111A22222222";

NSArray*array = [string componentsSeparatedByString:@"A"];//從字符A中分隔成2個(gè)元素的數(shù)組

NSLog(@"array:%@",array);

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

NSLog(@"array2 ==== %@",[array lastObject]);

5.驗(yàn)證

NSString*str1 =@"http:www.baidu.com";

BOOL a = [str1 hasPrefix:@"http"];//是否是以http開頭

BOOL b = [str1 hasSuffix:@"com"];//文件路徑是否以com結(jié)尾

NSLog(@"a ===== %d ,b ==== %d",a,b);

6.改變字符串的大小寫

NSString* str2 =@"beiJING";

NSString*da = [str2 uppercaseString];//轉(zhuǎn)成大寫

NSString*xiao = [str2 lowercaseString];//轉(zhuǎn)成小寫

NSString*shouDa = [str2 capitalizedString];//首字母大寫，其余小寫

NSLog(@"\n大寫==%@\n小寫=== %@\n首字母大寫其余小寫=== %@",da,xiao,shouDa);

7.編碼，解碼

編碼

NSString*hStr =@"你好啊";

NSString*hString = [hStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

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

解碼

NSString*str3 =@"\u5982\u4f55\u8054\u7cfb\u5ba2\u670d\u4eba\u5458\uff1f";

NSString*str5 = [str3stringByReplacingPercentEscapesUsingEncoding:NSUTF8StringEncoding];

NSLog(@"string ==== %@",str5);