1. 从字符串“123-456-789-000”中提取数字部分，组成新的输出字符串
NSString *str=[[NSString alloc]initWithFormat:@"123-456-789-000"]; NSArray *arr=[str componentsSeparatedByString:@"-"]; NSLog(@"%@%@%@%@",[arr objectAtIndex:0],[arr objectAtIndex:1],[arr objectAtIndex:2],[arr objectAtIndex:3]); NSString *newStr=[str stringByReplacingOccurrencesOfString:@"-" withString:@""]; NSLog(@"%@",newStr);
2. 将四个十进制三位数添加到数组中，按从小到大排序后组成新的数组
#import int main(int argc, const char * argv[]) { @autoreleasepool { NSMutableArray *arr=[[NSMutableArray alloc]initWithObjects:@"123",@"234",@"110",@"142", nil]; for(int i=0;i<[arr count]-1;i++){ for(int j=0;j<[arr count]-i-1;j++){ NSComparisonResult result=[[arr objectAtIndex:j] compare:[arr objectAtIndex:j+1]]; if(result==NSOrderedDescending){ [arr exchangeObjectAtIndex:j+1 withObjectAtIndex:j]; } } } for(int i=0;i<[arr count];i++){ NSLog(@"%@",[arr objectAtIndex:i]); } } return 0; } 