字符串的一些常用方法

//字符串的其他常用方法

//1.字符串的转换函数

NSString *str1 = @"111add333";

int a1 = [str1 intValue];

float b1 = [str1 floatValue];

double c1 = [str1 doubleValue];

NSLog(@"%d",a1);

//2.字符串大小写转换函数

NSString *str2 = @"aaabb";

NSString *str3 = [str2 uppercaseString]; //将字符全部改写成大写

NSLog(@"str3 = %@",str3);

NSString *str4 = [str3 lowercaseString]; //将字符全部改写成小写

NSLog(@"str4 = %@",str4);

NSString *str5 = [str2 capitalizedString]; //将首个字符改写成大写，其余的都小写

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

//字符串的替换函数

NSString *str6 = [str2 stringByReplacingOccurrencesOfString:@"bb" withString:@"dd"];

NSLog(@"str6 = %@",str6);

NSString *str7 = [str2 stringByReplacingCharactersInRange:NSMakeRange(1, 2) withString:@"cc"]; //将原字符串中range范围内的内容替换成replacement的内容

NSLog(@"str7 = %@",str7);

NSString *str8 = @"aa-bb-cc-dd-ee";

NSArray *array = [str8 componentsSeparatedByString:@"-"];

//以separator为分隔符，将原字符串的内容进行分割，分割得到的结果放到一个数组里，作为返回值

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