ObjectiveC開發教程--字符串的基本操作處理方法
//一、NSString
/*----------------創建字符串的方法----------------*/
//1、創建常量字符串。
NSString *astring = @This is a String!;
//2、創建空字符串，給予賦值。
NSString *astring = [[NSString alloc] init];
astring = @This is a String!;
[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、用標准c創建字符串:initWithCString方法
char *Cstring = This is a String!;
NSString *astring = [[NSString alloc] initWithCString:Cstring];
NSLog(@astring:%@,astring);
[astring release];
//5、創建格式化字符串:占位符（由一個%加一個字符組成）
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、創建臨時字符串
NSString *astring;
astring = [NSString stringWithCString:This is a temporary string];
NSLog(@astring:%@,astring);
/*----------------從文件讀取字符串:initWithContentsOfFile方法----------------*/
NSString *path = @astring.text;
NSString *astring = [[NSString alloc] initWithContentsOfFile:path];
NSLog(@astring:%@,astring);
[astring release];
/*----------------寫字符串到文件:writeToFile方法----------------*/
NSString *astring = [[NSString alloc] initWithString:@This is a String!];
NSLog(@astring:%@,astring);
NSString *path = @astring.text;
[astring writeToFile: path atomically: YES];
[astring release];
/*----------------比較兩個字符串----------------*/
//用C比較:strcmp函數
char string1[] = string!;
char string2[] = string!;
if(strcmp(string1, string2) = = 0)
{
NSLog(@1);
}
//isEqualToString方法
NSString *astring01 = @This is a String!;
NSString *astring02 = @This is a String!;
BOOL result = [astring01 isEqualToString:astring02];
NSLog(@result:%d,result);
//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;
NSLog(@result:%d,result);
//NSOrderedSame判斷兩者內容是否相同
NSString *astring01 = @This is a String!;
NSString *astring02 = @this is a String!;
BOOL result = [astring01 compare:astring02] = = NSOrderedAscending;
NSLog(@result:%d,result);
//NSOrderedAscending判斷兩對象值的大小(按字母順序進行比較，astring02大於astring01為真)
NSString *astring01 = @this is a String!;
NSString *astring02 = @This is a String!;
BOOL result = [astring01 compare:astring02] = = NSOrderedDescending;
NSLog(@result:%d,result);
//NSOrderedDescending判斷兩對象值的大小(按字母順序進行比較，astring02小於astring01為真)
//不考慮大小寫比較字符串1
NSString *astring01 = @this is a String!;
NSString *astring02 = @This is a String!;
BOOL result = [astring01 caseInsensitiveCompare:astring02] = = NSOrderedSame;
NSLog(@result:%d,result);
//NSOrderedDescending判斷兩對象值的大小(按字母順序進行比較，astring02小於astring01為真)
//不考慮大小寫比較字符串2
NSString *astring01 = @this is a String!;
NSString *astring02 = @This is a String!;
BOOL result = [astring01 compare:astring02
options:NSCaseInsensitiveSearch | NSNumericSearch] = = NSOrderedSame;
NSLog(@result:%d,result);
//NSCaseInsensitiveSearch:不區分大小寫比較 NSLiteralSearch:進行完全比較，區分大小寫 NSNumericSearch:比較字符串的字符個數，而不是字符值。
/*----------------改變字符串的大小寫----------------*/
NSString *string1 = @A String;
NSString *string2 = @String;
NSLog(@string1:%@,[string1 uppercaseString]);//大寫
NSLog(@string2:%@,[string2 lowercaseString]);//小寫
NSLog(@string2:%@,[string2 capitalizedString]);//首字母大小
/*---------------在串中搜索子串----------------*/
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];
/*----------------抽取子串 ----------------*/
//-substringToIndex: 從字符串的開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);
//-substringFromIndex: 以指定位置開始（包括指定位置的字符），並包括之後的全部字符
NSString *string1 = @This is a string;
NSString *string2 = [string1 substringFromIndex:3];
NSLog(@string2:%@,string2);
//-substringWithRange: //按照所給出的位置，長度，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);
//擴展路徑
NSString *Path = @~/NSData.txt;
NSString *absolutePath = [Path stringByExpandingTildeInPath];
NSLog(@absolutePath:%@,absolutePath);
NSLog(@Path:%@,[absolutePath stringByAbbreviatingWithTildeInPath]);
//文件擴展名
NSString *Path = @~/NSData.txt;
NSLog(@Extension:%@,[Path pathExtension]);
/*******************************************************************************************
NSMutableString
*******************************************************************************************/
/*---------------給字符串分配容量----------------*/
//stringWithCapacity:
NSMutableString *String;
String = [NSMutableString stringWithCapacity:40];
/*---------------在已有字符串後面添加字符----------------*/
//appendString: and appendFormat:
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);
*/
/*--------在已有字符串中按照所給出范圍和長度刪除字符------*/
/*
//deleteCharactersInRange:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@This is a NSMutableString];
[String1 deleteCharactersInRange:NSMakeRange(0, 5)];
NSLog(@String1:%@,String1);
/*--------在已有字符串後面在所指定的位置中插入給出的字符串------*/
//-insertString: atIndex:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@This is a NSMutableString];
[String1 insertString:@Hi! atIndex:0];
NSLog(@String1:%@,String1);
/*--------將已有的空符串換成其它的字符串------*/
//-setString:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@This is a NSMutableString];
[String1 setString:@Hello Word!];
NSLog(@String1:%@,String1);
/*--------按照所給出的范圍，和字符串替換的原有的字符------*/
//-setString:
NSMutableString *String1 = [[NSMutableString alloc] initWithString:@This is a NSMutableString];
[String1 replaceCharactersInRange:NSMakeRange(0, 4) withString:@That];
NSLog(@String1:%@,String1);
/*-------------判斷字符串內是否還包含別的字符串(前綴，後綴)-------------*/
//01：檢查字符串是否以另一個字符串開頭- (BOOL) hasPrefix: (NSString *) aString;
NSString *String1 = @NSStringInformation.txt;
[String1 hasPrefix:@NSString] = = 1 ?NSLog(@YES) : NSLog(@NO);
[String1 hasSuffix:@.txt] = = 1 ?NSLog(@YES) : NSLog(@NO);
