数据类型转换

import “RootViewController.h”

@interface RootViewController ()

@end

@implementation RootViewController

(void)viewDidLoad {

[super viewDidLoad];

// Do any additional setup after loading the view.

//[b]********************NSString 相关***********************[/b]//

//NSDictionary 转NSString

//用字符串将nsarray的元素拼接起来

NSArray *array = [NSArray arrayWithObjects:@”hello”,@”world”, nil];

NSString *string = [array componentsJoinedByString:@” “];

NSLog(@”string = %@”,string );

//nsdata 转 nsstring

NSString *strurl = @”www.”;

NSURL *url = [NSURL URLWithString:strurl];

NSData *data = [NSData dataWithContentsOfURL:url];

NSString *datastr1 = [[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];

// NSString 转换成NSData 对象

NSData* Data = [@”testdata” dataUsingEncoding:NSUTF8StringEncoding];

// NSData 转换成char*

NSData *data2;

const char* a=[data2 bytes];

//nsstring zhuan char

NSString *str = @”dad”;

const char *q =[str UTF8String];

// char* 转换成NSData对象

Byte* tempData = malloc(sizeof(Byte)*16);

NSData *content=[NSData dataWithBytes:tempData length:16];

// 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 = [[NSNumberFormatter alloc] init];
NSNumber *A = [[NSNumber alloc]initWithInt:5];
NSString *B;
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];

// 5，万能公式其他转字符

NSString *stringFloat = [NSString stringWithFormat:@"%f",floatString];

//

}

//nsdictionary 相关

//字典nsdictionary 转成json

- (NSString )dictionaryToJason:(NSDictionary )dic

{

NSData *jsondata = [NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPrettyPrinted error:nil];

return [[NSString alloc]initWithData:jsondata encoding:NSUTF8StringEncoding];

}

(void)didReceiveMemoryWarning {

[super didReceiveMemoryWarning];

// Dispose of any resources that can be recreated.

}

/*

pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

// Get the new view controller using [segue destinationViewController].

// Pass the selected object to the new view controller.

}

*/

@end