iOS开发NSString篇：字符串每隔几个字符插入某个字符

算法思路：

iOS代码实现：

//每隔4个字符添加一个空格的字符串算法
- (NSString *)dealWithString:(NSString *)number
{
NSString *doneTitle = @"";
int count = 0;
for (int i = 0; i < number.length; i++) {

count++;
doneTitle = [doneTitle stringByAppendingString:[number substringWithRange:NSMakeRange(i, 1)]];
if (count == 4) {
doneTitle = [NSString stringWithFormat:@"%@ ", doneTitle];
count = 0;
}
}
NSLog(@"%@", doneTitle);
return doneTitle;
}