在if之后如何在android中设置日期条件

我提出了一个申请，我把每月的第二天条件放在（如果）后面，像这样

if (cal.get(Calendar.DAY_OF_MONTH) == 9) {
        Intent intent1 = new Intent(MainActivity.this, TextActivity.class);
        intent1.putExtra("key", getResources().getString(R.string.s_monday_txt));
        startActivity(intent1);
        finish();
    } else if (cal.get(Calendar.DAY_OF_MONTH) == 10) {
        Intent intent2 = new Intent(MainActivity.this, TextActivity.class);
        intent2.putExtra("key", getResources().getString(R.string.s_tuesday_txt));
        startActivity(intent2);
        finish();
    }

    if (cal.get(Calendar.MONTH) == Calendar.SEPTEMBER) {
        Intent intent1 = new Intent(MainActivity.this, TextActivity.class);
        intent1.putExtra("key", getResources().getString(R.string.s_september_txt));
        startActivity(intent1);
        finish();
    } else if (cal.get(Calendar.MONTH) == Calendar.AUGUST) {
        Intent intent2 = new Intent(MainActivity.this, TextActivity.class);
        intent2.putExtra("key", getResources().getString(R.string.s_august_txt));
        startActivity(intent2);
        finish();
    }

if (cal.get(Calendar.MONTH) == Calendar.SEPTEMBER) + (cal.get(Calendar.DAY_OF_MONTH) == 9) {
        Intent intent1 = new Intent(MainActivity.this, TextActivity.class);
        intent1.putExtra("key", getResources().getString(R.string.s_september_txt));
        startActivity(intent1);
        finish();
    } else if (cal.get(Calendar.MONTH) == Calendar.AUGUST)  + (cal.get(Calendar.DAY_OF_MONTH) == 10) {
        Intent intent2 = new Intent(MainActivity.this, TextActivity.class);
        intent2.putExtra("key", getResources().getString(R.string.s_august_txt));
        startActivity(intent2);
        finish();
    }

在另一个地方，我把月份条件放在（如果）后面

if (cal.get(Calendar.DAY_OF_MONTH) == 9) {
        Intent intent1 = new Intent(MainActivity.this, TextActivity.class);
        intent1.putExtra("key", getResources().getString(R.string.s_monday_txt));
        startActivity(intent1);
        finish();
    } else if (cal.get(Calendar.DAY_OF_MONTH) == 10) {
        Intent intent2 = new Intent(MainActivity.this, TextActivity.class);
        intent2.putExtra("key", getResources().getString(R.string.s_tuesday_txt));
        startActivity(intent2);
        finish();
    }

    if (cal.get(Calendar.MONTH) == Calendar.SEPTEMBER) {
        Intent intent1 = new Intent(MainActivity.this, TextActivity.class);
        intent1.putExtra("key", getResources().getString(R.string.s_september_txt));
        startActivity(intent1);
        finish();
    } else if (cal.get(Calendar.MONTH) == Calendar.AUGUST) {
        Intent intent2 = new Intent(MainActivity.this, TextActivity.class);
        intent2.putExtra("key", getResources().getString(R.string.s_august_txt));
        startActivity(intent2);
        finish();
    }

if (cal.get(Calendar.MONTH) == Calendar.SEPTEMBER) + (cal.get(Calendar.DAY_OF_MONTH) == 9) {
        Intent intent1 = new Intent(MainActivity.this, TextActivity.class);
        intent1.putExtra("key", getResources().getString(R.string.s_september_txt));
        startActivity(intent1);
        finish();
    } else if (cal.get(Calendar.MONTH) == Calendar.AUGUST)  + (cal.get(Calendar.DAY_OF_MONTH) == 10) {
        Intent intent2 = new Intent(MainActivity.this, TextActivity.class);
        intent2.putExtra("key", getResources().getString(R.string.s_august_txt));
        startActivity(intent2);
        finish();
    }

这对我来说很好，但问题是我如何能像这样同时检查这两个条件

if (cal.get(Calendar.DAY_OF_MONTH) == 9) {
        Intent intent1 = new Intent(MainActivity.this, TextActivity.class);
        intent1.putExtra("key", getResources().getString(R.string.s_monday_txt));
        startActivity(intent1);
        finish();
    } else if (cal.get(Calendar.DAY_OF_MONTH) == 10) {
        Intent intent2 = new Intent(MainActivity.this, TextActivity.class);
        intent2.putExtra("key", getResources().getString(R.string.s_tuesday_txt));
        startActivity(intent2);
        finish();
    }

    if (cal.get(Calendar.MONTH) == Calendar.SEPTEMBER) {
        Intent intent1 = new Intent(MainActivity.this, TextActivity.class);
        intent1.putExtra("key", getResources().getString(R.string.s_september_txt));
        startActivity(intent1);
        finish();
    } else if (cal.get(Calendar.MONTH) == Calendar.AUGUST) {
        Intent intent2 = new Intent(MainActivity.this, TextActivity.class);
        intent2.putExtra("key", getResources().getString(R.string.s_august_txt));
        startActivity(intent2);
        finish();
    }

if (cal.get(Calendar.MONTH) == Calendar.SEPTEMBER) + (cal.get(Calendar.DAY_OF_MONTH) == 9) {
        Intent intent1 = new Intent(MainActivity.this, TextActivity.class);
        intent1.putExtra("key", getResources().getString(R.string.s_september_txt));
        startActivity(intent1);
        finish();
    } else if (cal.get(Calendar.MONTH) == Calendar.AUGUST)  + (cal.get(Calendar.DAY_OF_MONTH) == 10) {
        Intent intent2 = new Intent(MainActivity.this, TextActivity.class);
        intent2.putExtra("key", getResources().getString(R.string.s_august_txt));
        startActivity(intent2);
        finish();
    }

我试过（+），（和），（| |），（，）所有这些都不起作用

---

有什么帮助吗？

在java中，+符号是一个加法。如果需要“and”的含义，请使用&&符号

&&-及

||-或

因此，如果您想检查if语句中的两个条件是否都适用，请如下使用：

if (value == 1 && value2 == 1){
 // do something if value is equal to 1 _AND_ value2 equals to 1
}

---

对于和将其更改为

&&

，对于或将其更改为

|

在

cal.get（Calendar.MONTH）==Calendar.septer）+（Calendar.get（Calendar.DAY\u OF\u MONTH）==9中

将其更改为：

cal.get(Calendar.MONTH) == Calendar.SEPTEMBER) && (cal.get(Calendar.DAY_OF_MONTH) == 9

下面解释了
&&
，
| |
的含义。请根据您的要求使用运算符

if ((cal.get(Calendar.MONTH) == Calendar.SEPTEMBER) && (cal.get(Calendar.DAY_OF_MONTH) == 9)) {
 // it is  september and day of month is 9
}


if ((cal.get(Calendar.MONTH) == Calendar.SEPTEMBER) || (cal.get(Calendar.DAY_OF_MONTH) == 9)) {
 // either september or 9
}

参考
使用&&[你的意思是我这样说吗？如果（cal.get（Calendar.MONTH）=Calendar.Septer）和&（Calendar.get（Calendar.DAY，OF，OF，OF，MONTH）=9）{顺便说一句，你提供的网页没有打开你的意思是我这样说吗？如果（cal.get（Calendar.MONTH，Calendar.MONTH）=Calendar.Septer）和（Calendar.DAY，OF，OF，OF，OF，OF，MONTH）=9）{他们在get下面加下划线，这是他们给我的在类型Calendar中的方法get（int）不适用于参数（布尔值）您也没有正确使用括号。如果（cal.get（Calendar.MONTH）==Calendar.9ment&&cal.get（Calendar.DAY\u OF\u MONTH）==9{//do something}calc.get是一个函数，它将返回您将要检查的内容。另一个问题我可以在相同的条件下检查日期和月份吗？我强烈建议在做任何事情之前查阅一些有关Java的在线文档。语法，面向对象的思维是您要编码的必备工具。我收到了以下消息语法错误标记“&&”上的r无效，仅与红色下划线同步上面的代码缺少一些大括号，
&&&
，
|
用于布尔值。