//1、創(chuàng)建常量字符串。
NSString *astring = @"This is a String!";
//2、創(chuàng)建空字符串，給予賦值。
NSString *astring = [[NSString alloc] init];
astring = @"This is a String!";
[astring release];
NSLog(@"astring:%@",astring);
NSString *astring = [[NSString alloc] init];
NSLog(@"0x%.8x", astring);
astring=@"This is a String!";
NSLog(@"0x%.8x", astring);
[astring release];
NSLog(@"astring:%@",astring);
//3、在以上方法中，提升速度:initWithString方法
NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
NSLog(@"astring:%@",astring);
[astring release];
//4、用標(biāo)準(zhǔn)c創(chuàng)建字符串:initWithCString方法
char *Cstring = "This is a String!";
NSString *astring = [[NSString alloc] initWithCString:Cstring];
NSLog(@"astring:%@",astring);
[astring release];
//5、創(chuàng)建格式化字符串:占位符（由一個(gè)%加一個(gè)字符組成）
int i = 1;
int j = 2;
NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"%d.This is %i string!",i,j]];
NSLog(@"astring:%@",astring);
[astring release];
//6、創(chuàng)建臨時(shí)字符串
NSString *astring;
astring = [NSString stringWithCString:"This is a temporary string"];
NSLog(@"astring:%@",astring);
//7、從文件創(chuàng)建字符串
NSString *path = [[NSBundlemainBundle]pathForResource:@"astring.text"ofType:nil];
NSString *astring = [[NSString alloc] initWithContentsOfFile:path];
NSLog(@"astring:%@",astring);
[astring release];
//8、用字符串創(chuàng)建字符串，并寫(xiě)入到文件
NSString *astring = [[NSString alloc] initWithString:@"This is a String!"];
NSLog(@"astring:%@",astring);
NSString *path = @"astring.text";
[astring writeToFile: path atomically: YES];
[astring release];
注：此路徑path只只是示意，真實(shí)路徑并非如此
//9、用C比較:strcmp函數(shù)
char string1[] = "string!";
char string2[] = "string!";
if(strcmp(string1, string2) == 0)
{
NSLog(@"1");
}
//10、isEqualToString方法
NSString *astring01 = @"This is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 isEqualToString:astring02];
NSLog(@"result:%d",result);
//11、compare方法(comparer返回的三種值)
NSString *astring01 = @"This is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 compare:astring02] == NSOrderedSame;
//NSOrderedSame判斷兩者內(nèi)容是否相同
NSLog(@"result:%d",result);
//
NSString *astring01 = @"This is a String!";
NSString *astring02 = @"this is a String!";
BOOL result = [astring01 compare:astring02] == NSOrderedAscending; //NSOrderedAscending判斷兩對(duì)象值的大小(按字母順序進(jìn)行比較，astring02大于astring01為真)
NSLog(@"result:%d",result);
//
NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 compare:astring02] == NSOrderedDescending; //NSOrderedDescending判斷兩對(duì)象值的大小(按字母順序進(jìn)行比較，astring02小于astring01為真)
NSLog(@"result:%d",result);
//12、不考慮大小寫(xiě)比較字符串
//1.
NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 caseInsensitiveCompare:astring02] == NSOrderedSame; //NSOrderedDescending判斷兩對(duì)象值的大小(按字母順序進(jìn)行比較，astring02小于astring01為真)
NSLog(@"result:%d",result);
//2.
NSString *astring01 = @"this is a String!";
NSString *astring02 = @"This is a String!";
BOOL result = [astring01 compare:astring02
options:NSCaseInsensitiveSearch | NSNumericSearch] == NSOrderedSame; //NSCaseInsensitiveSearch:不區(qū)分大小寫(xiě)比較 NSLiteralSearch:進(jìn)行完全比較，區(qū)分大小寫(xiě) NSNumericSearch:比較字符串的字符個(gè)數(shù)，而不是字符值。
NSLog(@"result:%d",result);
//13、輸出大寫(xiě)或者小寫(xiě)字符串
NSString *string1 = @"A String";
NSString *string2 = @"String";
NSLog(@"string1:%@",[string1 uppercaseString]);//大寫(xiě)
NSLog(@"string2:%@",[string2 lowercaseString]);//小寫(xiě)
NSLog(@"string2:%@",[string2 capitalizedString]);//首字母大小
復(fù)制代碼
//14、-rangeOfString: //查找字符串某處是否包含其它字符串
NSString *string1 = @"This is a string";
NSString *string2 = @"string";
NSRange range = [string1 rangeOfString:string2];
int location = range.location;
int leight = range.length;
NSString *astring = [[NSString alloc] initWithString:[NSString stringWithFormat:@"Location:%i,Leight:%i",location,leight]];
NSLog(@"astring:%@",astring);
[astring release];
//15、-substringToIndex: 從字符串的開(kāi)頭一直截取到指定的位置，但不包括該位置的字符
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringToIndex:3];
NSLog(@"string2:%@",string2);
//16、-substringFromIndex: 以指定位置開(kāi)始（包括指定位置的字符），并包括之后的全部字符
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringFromIndex:3];
NSLog(@"string2:%@",string2);
//17、-substringWithRange: //按照所給出的位置，長(zhǎng)度，任意地從字符串中截取子串
NSString *string1 = @"This is a string";
NSString *string2 = [string1 substringWithRange:NSMakeRange(0, 4)];
NSLog(@"string2:%@",string2);
//18、-stringWithCapacity: //按照固定長(zhǎng)度生成空字符串
NSMutableString *String;
String = [NSMutableString stringWithCapacity:40];
//19、-appendString: and -appendFormat: //把一個(gè)字符串接在另一個(gè)字符串的末尾
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 appendString:@", I will be adding some character"];
[String1 appendFormat:[NSString stringWithFormat:@", I will be adding some character"]];
NSLog(@"String1:%@",String1);
//20、-insertString: atIndex: //在指定位置插入字符串
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 insertString:@"Hi! " atIndex:0];
NSLog(@"String1:%@",String1);
//21、-setString:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 setString:@"Hello Word!"];
NSLog(@"String1:%@",String1);
//22、-replaceCharactersInRange: withString: //用指定字符串替換字符串中某指定位置、長(zhǎng)度的字符串
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@"This is a NSMutableString"];
[String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@"That"];
NSLog(@"String1:%@",String1);
//23、-hasPrefix: //檢查字符串是否以另一個(gè)字符串開(kāi)頭
NSString *String1 = @"NSStringInformation.txt";
[String1 hasPrefix:@"NSString"] = = 1 ? NSLog(@"YES") : NSLog(@"NO");
[String1 hasSuffix:@".txt"] = = 1 ? NSLog(@"YES") : NSLog(@"NO");
//24、擴(kuò)展路徑
NSString *Path = @"~/NSData.txt";
NSString *absolutePath = [Path stringByExpandingTildeInPath];
NSLog(@"absolutePath:%@",absolutePath);
NSLog(@"Path:%@",[absolutePath stringByAbbreviatingWithTildeInPath]);
//25、文件擴(kuò)展名
NSString *Path = @"~/NSData.txt";
NSLog(@"Extension:%@",[Path pathExtension]);