/**
 *  判斷兩個浮點數是否整除
 *
 *  @param firstNumber  第一個浮點數(被除數)
 *  @param secondNumber 第二個浮點數(除數,不能為0)
 *
 *  @return 返回值可判定是否整除
 */
- (BOOL)judgeDivisibleWithFirstNumber:(CGFloat)firstNumber andSecondNumber:(CGFloat)secondNumber {
    // 預設記錄為整除
    BOOL isDivisible = YES;
    
    if (secondNumber == 0) {
        return NO;
    }
    
    CGFloat result = firstNumber / secondNumber;
    NSString * resultStr = [NSString stringWithFormat:@"%f", result];
    NSRange range = [resultStr rangeOfString:@"."];
    NSString * subStr = [resultStr substringFromIndex:range.location + 1];
    
    for (NSInteger index = 0; index < subStr.length; index ++) {
        unichar ch = [subStr characterAtIndex:index];
        
        // 後面的字元中只要有一個不為0，就可判定不能整除，跳出迴圈
        if ('0' != ch) {
            //            NSLog(@"不能整除");
            isDivisible = NO;
            break;
        }
    }
    
    // NSLog(@"可以整除");
    return isDivisible;
}