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];
四舍五入问题
-(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];
}
介绍一下参数：
price:需要处理的数字，
position：保留小数点第几位，
然后调用
float s =0.126;
NSString *sb = [self notRounding:s afterPoint:2];
NSLog(@"sb = %@",sb);
输出结果为：sb = 0.12
接下来介绍NSDecimalNumberHandler初始化时的关键参数：decimalNumberHandlerWithRoundingMode：NSRoundDown，
NSRoundDown代表的就是 只舍不入。
scale的参数position代表保留小数点后几位。
