字符串与数组的转换

1.将字符串数组，拼接成一个字符串

//中间以逗号隔开
NSString *departmentIdArrayStr = [arrM componentsJoinedByString:@","];

 

2.将字符串转换为数组

//以逗号为分隔标志
NSArray  *array = [@"" componentsSeparatedByString:@","];