对于浮动变量变为无穷大的嵌套if语句，我还有什么其他选择？

Question

I'm trying to construct a code for a float variables that does not rely on nested if statements unlike you can see in the following code-example.

As you can see the higher the velocity of the ball, the longer the code would get.

Is there a shorter way to write the code or do I have to use the nested if-else statement for the variable of ball_vector_x when going up to infinity or just as example up to 100?

counter is an int variable starting at zero

if(ball_vector_x == 4 || ball_vector_x == -4) {
    counter = 1;
  } else if(ball_vector_x == 5 || ball_vector_x == -5) {
    counter = 2;
  } else if(ball_vector_x == 6 || ball_vector_x == -6) {
    counter = 3;
  } else if(ball_vector_x == 7 || ball_vector_x == -7) {
    counter = 4;
  } else if(ball_vector_x == 8 || ball_vector_x == -8) {
    counter = 5;
  } else if(ball_vector_x == 9 || ball_vector_x == -9) {
    counter = 6;
  } else if(ball_vector_x == 10 || ball_vector_x == -10) {
    counter = 7;
  } else if(ball_vector_x == 11 || ball_vector_x == -11) {
    counter = 8;
  } else if(ball_vector_x == 12 || ball_vector_x == -12) {
    counter = 9;
  } else if(ball_vector_x == 13 || ball_vector_x == -13) {
    counter = 10;

Answer 1

看来您的计数器始终是矢量-3.您不能这样做

  counter = Math.abs(ball_vector_x)-3;

Answer 2

First: you can use Math.abs() to cut the number of comparisons by half.

And then you could use a map to store all these pairs for example.

But of course, the real answer is: you can express the relationship between those values using a simple formula. That is always the solution to look out for.

Finally: the point that the other answers are missing to explain -avoid comparing floating point numbers using ==. Use epsilon based comparison instead.

Answer 3

This will check if ball_vector_x is negative or positive and then set counter equal to the value of i.

if (ball_vector_x >= 0) {
    for (int i = 0; i < ball_vector_x; i++) {
        if(i == ball_vector_x) {
             counter = i - 3;
        }
    }
    else {
        for(int i = 0; i > ball_vector_x; i--) {
             if (i == ball_vector_x) {
                counter = (-1)*(i + 3); // I might've done the calculation       wrong here
        }
    }
}