float类型做比较

public class tst {
    private float a = 3.0f;
    private float b = 0.0f;
    private float c = 4.0f;
    private float d = 0.0f;

    public void floatCompare() {
        System.out.println("a>b:" + new Float(a).compareTo(new Float(b)));
        System.out.println("a<c:" + new Float(a).compareTo(new Float(c)));
        System.out.println("b=d:" + new Float(b).compareTo(new Float(d)));
    }

    public static void main(String args[]) {
        new tst().floatCompare();
    }
}

打印的结果：

a>b:1
a<c:-1
b=d:0

结论：如果比较值==1则前值大于后，==-1则前值小于后值，==0则两值相等

float类型数据做比较时，不能直接使用==号。