Objective-C中NSString與int和float的相互轉換

NSString *tempA = @"123";

NSString *tempB = @"456";

 

1，字符串拼接

 NSString *newString = [NSString stringWithFormat:@"%@%@",tempA,tempB];

 

2，字符轉int

int intString = [newString intValue];

 

3，int轉字符

NSString *stringInt = [NSString stringWithFormat:@"%d",intString];

 

4，字符轉float

 float floatString = [newString floatValue];

 

5，float轉字符

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

 

四舍五入問題

 

-(NSString *)notRounding:(float)price afterPoint:(int)position{

    NSDecimalNumberHandler* roundingBehavior = [NSDecimalNumberHandler decimalNumberHandlerWithRoundingMode:NSRoundDown scale:position raiseOnExactness:NO raiseOnOverflow:NO raiseOnUnderflow:NO raiseOnDivideByZero:NO];

    NSDecimalNumber *ouncesDecimal;

    NSDecimalNumber *roundedOunces;

    

    ouncesDecimal = [[NSDecimalNumber alloc] initWithFloat:price];

    roundedOunces = [ouncesDecimal decimalNumberByRoundingAccordingToBehavior:roundingBehavior];

    [ouncesDecimal release];

    return [NSString stringWithFormat:@"%@",roundedOunces];

}

介紹一下參數：

price:需要處理的數字，

position：保留小數點第幾位，

然后調用

 

    float s =0.126;

    NSString *sb = [self notRounding:s afterPoint:2];

    NSLog(@"sb = %@",sb);

輸出結果為：sb = 0.12

 

接下來介紹NSDecimalNumberHandler初始化時的關鍵參數：decimalNumberHandlerWithRoundingMode：NSRoundDown，

NSRoundDown代表的就是 只舍不入。

scale的參數position代表保留小數點后幾位。