public boolean equals(Object anObject) { if (this == anObject) { return true; } if (anObject instanceof String) { String anotherString = (String)anObject; int n = value.length; if (n == anotherString.value.length) { char v1[] = value; char v2[] = anotherString.value; int i = 0; while (n-- != 0) { if (v1[i] != v2[i]) return false; i++; } return true; } } return false; }
这个可以这么解释:
//重写toString方法的作用就是打印出具体的信息 @Override public String toString() { return "User{" + "name='" + name + '\'' + ", phoneNum='" + phoneNum + '\'' + '}'; }
解决了打印为null的问题: