1.截取字符串
//截取掉下標(biāo)7之前的字符串
NSString *string1 = @"123456789";
string1 = [string1? substringToIndex:7];//（length為7）
NSLog(@"截取的值為：%@",string1);//輸出結(jié)果為1234567
//截取掉下標(biāo)2之后的字符串
NSString *string2 = @"123456789";
string2? = [string2 substringFromIndex:2];
NSLog(@"截取的值為：%@",string2);//輸出結(jié)果為3456789
//截取字符串最后3位
NSString *string3 = @"123456789";
string3 = [string3 substringFromIndex:string3.length- 3];
NSLog(@"截取的值為：%@",string3);//輸出結(jié)果為789
//即當(dāng)截取字符串后n位時(shí),公式為：
//string = [sting substringfromIndex:string.length-n];
2.匹配字符串
NSString *string = @"18355161287";
//匹配得到的下標(biāo)
NSRange range = [string rangeOfString:@"2"];
NSLog(@"range:%@",NSStringFromRange(range));//輸出結(jié)果為{8,1}
NSRange range2 = [string rangeOfString:@"12"];
NSLog(@"%@",NSStringFromRange(range2));//輸出結(jié)果為{7，2}
NSString *string1 = [string substringWithRange:range];//截取范圍內(nèi)的字符串
NSLog(@"截取的值為：%@",string1);//輸出的值為2
3.替換中間部分字符
NSString *string = @"18355161287";
NSString *numberString = [string stringByReplacingCharactersInRange:NSMakeRange(3, 4) withString:@"****"]; //隱藏手機(jī)號(hào)中間四位數(shù)
NSLog(@"%@",numberString);//輸出結(jié)果為183****1287
4.分隔字符串
NSString *string = @"18355161287";
NSArray *array = [string componentsSeparatedByString:@"8"];
NSLog(@"%@",array);//輸出結(jié)果(1,3551612,7)
5.拼接字符串
NSString *sting1 = @"1835516";
NSString *string2 = @"1287";
NSString *string = [string1 stringByAppendingString:string2];
//NSString *string = [NSString stringWithFormat:@"%@%@",string1,string2];
//如果是可變字符串可用：[string1 appendString:string2]
NSLog(@"%@",string); //輸出結(jié)果為18355161287
6.字符串大小寫轉(zhuǎn)換
NSString *string1 = @"abcd123";
NSString *string2 = @"XYZQ456";
//將字符串的英文字符由小寫轉(zhuǎn)換成大寫
NSString *bigString = [string1 uppercaseString];
NSLog(@"%@",bigString); //輸出結(jié)果為ABCD123
//將字符串的英文字符由大寫轉(zhuǎn)換為小寫
NSString *smallString = [string2 lowercaseString];
NSLog(@"%@",smallString);//輸出結(jié)果為xyzq456
//將字符串的首字母改為大寫
NSString *firstbig = [string1 capitalizedString];
NSLog(@"%@",firstbig);//輸出結(jié)果為Abcd123
7.可變字符串的增刪改查
//可變字符串拼接
NSMutableString *string = [[NSMutableString alloc]initWithString:@"123"];
[string appendString:@"45"];
NSLog(@"%@",string);//輸出結(jié)果12345
//可變字符串替換
NSMutableString *string2 = [[NSMutableString alloc]initWithString:@"123"];
[string2 replaceCharactersInRange:NSMakeRange(1,2) withString:@"78"];
NSLog(@"%@",string2); //輸出結(jié)果178
//可變字符串的插入
NSMutableString *string3 = [[NSMutableString alloc]initWithString:@"123"];
[string3 insertString:@"56" atIndex:1];
NSLog(@"%@",string3);//輸出結(jié)果15623
//可變字符串刪除字符串
NSMutableString *string4 = [[NSMutableString alloc]initWithString:@"123"];
[string4 deleteCharactersInRange:NSMakeRange(1, 1)];
NSLog(@"%@",string4);//輸出結(jié)果13
8.給字符串某段字符潤(rùn)色
NSString *contentStr = @"已閱讀并同意聚奢網(wǎng)平臺(tái)協(xié)議";
NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:contentStr];
[str addAttribute:NSForegroundColorAttributeName value:[UIColor grayColor] range:NSMakeRange(0, 6)];
//同樣如果是改變字符串中某段字體的大小可以這樣寫：
[str addAttribute:NSFontAttributeName value:[UIFont SystemFontOfSize:20] range:NSMakeRange(0, 6)];
