摘要：
package cty; public class L { public int id; public String name; public int age; public String city ; public String introduce (){ return +id+"我"+name+ 阅读全文
摘要：
public double len(){ double length; length = Math.sqrt(this.x * this.y); return length; public void nor(){ this.x = this.x / length; this.y = this.y / 阅读全文