Objective-C中整数与字符串的相互转换

2013/4/15整理：

 

将整数转换成字符串 Convert Integer to NSString:

方法一：

int Value = 112233;

NSString *ValueString = [NSString stringWithFormat:@"%d", Value];

方法二：

[[NSNumber numberWithInt: 123] stringValue];

 

得到C风格的字符串 C String

char *ValueasCString = (char *)[ValueString UTF8String];

 

将字符串转换成整数或浮点数

Convert String to Integer or float

NSString has some useful methods:

-(int) intValue

-(float) floatValue

NSString *aNumberString = @"123";

int i = [aNumberString intValue];

 

字符串转换为日期

NSDateFormatter* dateFormat = [[NSDateFormatter alloc] init];//实例化一个NSDateFormatter对象

[dateFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss"];//设定时间格式,这里可以设置成自己需要的格式

NSDate *date =[dateFormat dateFromString:@"1980-01-01 00:00:01"];

 

日期转换为字符串

NSDateFormatter* dateFormat = [[NSDateFormatter alloc] init];//实例化一个NSDateFormatter对象

[dateFormat setDateFormat:@"yyyy-MM-dd HH:mm:ss"];//设定时间格式,这里可以设置成自己需要的格式

NSString *currentDateStr = [dateFormat stringFromDate:[NSDate date]];

 

使用NSNumberFormatter将数值转换成字符串

Simplifying NSNumberFormatter Use on the iPhone With Objective-C Categories

http://forgecode.net/2010/02/simplifying-nsnumberformatter-use-on-the-iphone-with-objective-c-categories/

Here are the different formatter styles, and the result when converting [NSNumber numberWithDouble:123.4] into an NSString.

NSNumberFormatterNoStyle (123)

NSNumberFormatterDecimalStyle (123.4)

NSNumberFormatterCurrencyStyle ($123.40)

NSNumberFormatterPercentStyle (12,340%)

NSNumberFormatterScientificStyle (1.234E2)

NSNumberFormatterSpellOutStyle (one hundred and twenty-three point four)

NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];

formatter.numberStyle = NSNumberFormatterCurrencyStyle;

NSString *string = [formatter stringFromNumber:number];

[formatter release];