NSNumber转NSString:
假设现有一NSNumber的变量A，要转换成NSString类型的B
方法如下：
NSNumberFormatter* numberFormatter = [[NSNumberFormatteralloc] init];
B = [numberFormatter stringFromNumber:A];
[numberFormatter release];
nsstring和float 还有int之间的转换
NSString *tempA = @"123";
NSString *tempB = @"456";
1，字符串拼接
NSString *newString = [NSString stringWithFormat:@"%@%@",tempA,tempB];
2，字符转int
int intString = [newString intValue];
3，int转字符
NSString *stringInt = [NSString stringWithFormat:@"%d",intString];
4，字符转float
float floatString = [newString floatValue];
5，float转字符
NSString *stringFloat = [NSString stringWithFormat:@"%f",intString];
原文：http://www.cnblogs.com/shaowenlong/p/5116428.html