-NSString
1.NSString 創(chuàng)建:
//直接賦值
NSString *str1 = @"Hello world 1";
// 用一個(gè)字符串創(chuàng)建一個(gè)新的字符串 這樣的str1和str2指向同一個(gè)地址中的字符串
NSString *str2 = [[NSString alloc]initWithString:str1];
//用C語言的字符串創(chuàng)建一個(gè)字符串
NSString *str3 = [[NSString alloc] initWithUTF8String:"Hello world 3"];
//用格式符拼接一個(gè)字符串
NSString *str4 = [[NSString alloc] initWithFormat:@"hello worl%c %d",'d',4];
//創(chuàng)建臨時(shí)字符串的三種方法 ----系統(tǒng)不知道什么時(shí)候會將臨時(shí)字符串釋放掉
NSString *str5 = [NSString stringWithString:str1];
NSString *str6 = [NSString stringWithFormat:@"hello world %d" , 6];
NSString *str7 = [NSString stringWithUTF8String:"hello world 7"];
2.字符串比較:
NSString *compareStr1 = @"3356";
NSString *compareStr2 = @"456";
//字符串比較
BOOL res1 = [compareStr1 compare:compareStr2];
//字符串比較 帶選項(xiàng)比較,后面可以了解optis的選擇
BOOL res2 = [compareStr1 compare:compareStr2 options:NSNumericSearch];
NSLog(@"%d %d",res1,res2); //-1 1
3.查找子字符串位置 (字符串位置從0開始)
NSString *superStr = @"my name is CodingEleven!";
NSString *subStr = @"Co";
//獲取指定子字符串的位置和長度
NSRange subRange = [superStr rangeOfString:subStr];
NSLog(@"%ld %ld",subRange.location,subRange.length); //11 2
4.提取子字符串方法:
NSString *superStr1 = @"0123456789";
//從superStr1提取第0~6個(gè)字符串(不包括第6個(gè)字符),生成新字符串,并返回新字符串地址
NSString *subStr1 = [superStr1 substringToIndex:6];
NSLog(@"%@",subStr1); //012345
//從第6個(gè)字符到最后一個(gè)字符(包括第6個(gè)字符),生成新字符串,并返回新字符串地址
NSString *subStr2 = [superStr1 substringFromIndex:6];
NSLog(@"%@",subStr2); //6789
//從第3個(gè)字符開始,提取4個(gè)字符,生成新字符串
NSString *subStr3 = [superStr1 substringWithRange:NSMakeRange(3, 4)];
NSLog(@"%@",subStr3); //3456
5.大小寫轉(zhuǎn)換
//小寫轉(zhuǎn)大寫
NSString *str1 = @"hello world";
NSString *newStr1 = [str1 uppercaseString];
NSLog(@"%@",newStr1); //HELLO WORLD
//大寫轉(zhuǎn)小寫
NSString *str2 = @"HELLO WORLD";
NSString *newStr2 = [str2 lowercaseString];
NSLog(@"%@",newStr2); //hello world
6.NSString轉(zhuǎn)NSInteger
//字符串轉(zhuǎn)化成整形
NSString *str10 = @"1234";
NSInteger num = [str10 integerValue];
NSLog(@"num = %ld",num); //num = 1234
-NSMutableString
NSMutableString能用NSString的全部方法
1.創(chuàng)建可變字符串
//創(chuàng)建NSMutableString并設(shè)置字符串內(nèi)容
NSMutableString *str11 = [[NSMutableString alloc] init];
[str11 setString:@"我是孩子"];
2.插入字符串(直接修改原字符串)
[str11 insertString:@"好" atIndex:2];
NSLog(@"%@",str11); //我是好孩子
3.追加字符串
//追加字符串
[str11 appendString:@",而且很乖"];
NSLog(@"%@",str11); //我是好孩子,而且很乖
//格式化追加
[str11 appendFormat:@",今年%d歲",5];
NSLog(@"%@",str11); //我是好孩子,而且很乖,今年5歲
4.刪除
//包括第5個(gè)
[str11 deleteCharactersInRange:NSMakeRange(5, 5)];
NSLog(@"%@",str11);//我是好孩子,今年5歲
5.替換
//把一個(gè)區(qū)間內(nèi)的字符串替換掉
[str11 replaceCharactersInRange:NSMakeRange(2, 3) withString:@"CodingEleven"];
NSLog(@"%@",str11); //我是CodingEleven,今年5歲
6.查找替換
NSMutableString *str12 = [[NSMutableString alloc]initWithString:@"吃葡萄不吐葡萄皮"];
/*
參數(shù)1:要替換的字符串
參數(shù)2:替換的字符串
參數(shù)3:替換規(guī)則NSLiteralSearch
參數(shù)4:查找區(qū)間
*/
[str12 replaceOccurrencesOfString:@"葡萄" withString:@"西瓜" options:NSLiteralSearch range:[str12 rangeOfString:str12]];
NSLog(@"%@",str12);//吃西瓜不吐西瓜皮
