int main(void)
{
	using namespace std;
	int n(3); // C++還可以這么賦值
	int m{6};
	int f = {8};
	int n_int = INT_MAX; //聲明變量同時賦值=初始化
	short n_short = SHRT_MAX;
	long n_long = LONG_MAX;
	long long n_llong = LLONG_MAX;
	cout << "n = " << n << endl;
	cout << "m = " << m << endl;
	cout << "f = " << f << endl;
	cout << "int is " << sizeof(int) << " bytes." << endl;		// sizeof是運算符不是clmits中的函數(shù).INT_MAX是
	cout << "short is " << sizeof n_short << " bytes." << endl; //函數(shù)必須帶括號，sizeof(運算符)在這里可以不跟括號，但查看數(shù)據(jù)類型必須加括號
	cout << "long is " << sizeof n_long << " bytes." << endl;
	cout << "long long is " << sizeof n_llong << " bytes." << endl;
	cout << "Maximum values: " << endl;
	cout << "int: " << n_int << endl;
	cout << "short: " << n_short << endl;
	cout << "long: " << n_long << endl;
	cout << "long long: " << n_llong << endl;
	return 0;
}

#include <iostream>
#include <climits> //可以查看數(shù)據(jù)類型最大值最小值
int main(void)
{
	using namespace std;
	short sam = SHRT_MAX;	  //-32768-32767 （16位）   longlong > long（至少32位）> int > short（至少16位）
	unsigned short sue = sam; // 0-65535
	cout << "sam has " << sam << " dolloars and sue has " << sue << " dolloars" << endl;
	cout << "Add 1 dolloars to each account" << endl;
	sam = sam + 1;
	sue = sue + 1;
	cout << "Now sam has " << sam << " dolloars and sue has " << sue << " dolloars" << endl;
	sam = 0;
	sue = 0;
	sam = sam - 1;
	sue = sue - 1;
	cout << "Now sam has " << sam << " dolloars and sue has " << sue << " dolloars" << endl;
	return 0;
}

#include <iostream>
int main(void)
{
	using namespace std;
	int cheat = 42;	  //十進制
	int waist = 0x42; //十六進制
	int inseam = 042; //八進制
	cout << hex; //修改cout顯示整數(shù)的方式
	cout << "cheat = " << cheat << " 42 (in decimal)" << endl;
	cout << "waist = " << waist << " 0x42 (in hexadicimal)" << endl;
	cout << "inseam = " << inseam << " 042 (in octal)" << endl; // cout默認以十進制顯示整數(shù)
	return 0;
}

#include <iostream>
int main(void)
{
	using namespace std;
	int cheat = 42;
	int waist = 0x42;
	int inseam = 042;
	cout << "cheat = " << cheat << " 42 (in decimal)" << endl; // cout默認十進制顯示
	cout << hex; //修改cout為十六進制顯示
	cout << "waist = " << waist << " 0x42 (in hexadicimal)" << endl;
	cout << oct; //修改cout為八進制顯示
	cout << "inseam = " << inseam << " 042 (in octal)" << endl;
	return 0;
}

#include <iostream>
int main(void)
{
	using namespace std;
	char ch;
	cout << "Enter a character:" << endl;
	cin >> ch;    //cin將鍵盤輸入的M轉(zhuǎn)換為77
	cout << "Hello, thanks you for the " << ch << " character." << endl; //cout將77轉(zhuǎn)換為M，cin和cout的行為由變量類型引導
	return 0;
}

#include <iostream>
int main()
{
	using namespace std;
	char ch = 'M';
	int i = ch;
	cout << "The ASCII code for " << ch << " is " << i << endl;
	cout << "Add one to the character code:" << endl;
	ch = ch + 1; //顯示下一個字符
	i = ch;
	cout << "The ASCII code for " << ch << " is " << i << endl;
	cout << "Displaying char ch using cout.put(ch)" << endl; // iostream類(數(shù)據(jù)以及操作數(shù)據(jù)的方法)的對象cin、cout    矩形（對象）平移（方法）
	cout.put(ch); //用對象訪問類里面的操作方法（函數(shù)）、
	cout.put('!');
	cout.put('A');
	cout << "Done" << endl;
	return 0;
}

#include <iostream>
int main(void)
{
	using namespace std;
	int n = 10;
	cout << "Hello world!" << endl;
	cout << "Good morning!\n";//使用轉(zhuǎn)義字符換行,顯示字符串這種方法簡單一點，\n是一個字符哦（換行符）
	cout << "What's your name?" << '\n';
	cout << "What's your name?" << "\n";
	cout << "n = " << n << endl;
	cout << "n = " << n << "\n";
	return 0;
}

#include <iostream>
int main()
{
    using namespace std;
    const int toes = 10; //必須在聲明時賦值（之后不準修改）（對const初始化）
    /*const int toes;
    toes = 10;這種是錯誤的*/
    return 0;
}

#include <iostream>
int main()
{
    using namespace std;
    cout.setf(ios_base::fixed, ios_base::floatfield);
    float tub = 10.0 / 3.0;
    const float million = 1.0E6;
    cout << "tub = " << tub << endl;                             // cout默認輸出小數(shù)點后六位
    cout << "A million tubs = " << million * tub << endl;        // float精度達不到
    cout << "Ten million tubs = " << 10 * million * tub << endl; // float精度達不到
    double mint = 10.0 / 3.0;
    cout << "A million mint = " << million * mint << endl;
    cout << "Ten million mint = " << 10 * million * mint << endl; // double精度比float高
    return 0;
}

#include <iostream>
int main()
{
    using namespace std;
    float a = 2.34E22; // 2.34e/E+22   2.34*10^22
    float b = a + 1.0;
    cout << "a = " << a << endl;
    cout << "b = " << b << endl;          //a = b
    cout << "b - a = " << b - a << endl; // float位數(shù)只有前六位或前七位有效
    return 0;
}

/*
 * @Description:
 * @Date: 2022-02-14 13:25:40
 * @LastEditTime: 2022-02-14 13:56:58
 * @FilePath: \C++\第三章\class6\6_1.cpp
 */
// 26.0在內(nèi)存中如何存儲的？ 11010.00000000............ 1.10100.......0 * 2 ^ 4 符號位：0 指數(shù)位：127 + 4 = 131 二進制：10000011 小數(shù)位：010000000000...........
#include <iostream>
int main(void)
{
    using namespace std;
    float hats, heads;
    cout.setf(ios_base::fixed, ios_base::floatfield); //可以強制打印小數(shù)點后六位（沒辦法四舍五入）,去掉這一句就可以四舍五入，輸出61.42000000.......0可以不顯示
    cout << "Enter a number: "; // 50.25
    cin >> hats;
    cout << "Enter another number: "; // 11.17
    cin >> heads;
    cout << "hats = " << hats << " heads = " << heads << endl;
    cout << "hats + heads = " << hats + heads << endl; // 61.42  的小數(shù)部分 0.42 二進制01101...........無限，但是float二進制小數(shù)部分只有23位有效，十進制六位61.4199（近似有效）
    cout << "hats - heads = " << hats - heads << endl;
    cout << "hats * heads = " << hats * heads << endl;
    cout << "hats / heads = " << hats / heads << endl; // folat精度不夠，二進制只能顯示小數(shù)點后23位，所以不準，去掉setf（）可四舍五入
    return 0;
}

#include <iostream>
int main(void)
{
    using namespace std;
    cout.setf(ios_base::fixed, ios_base::floatfield); //顯示小數(shù)點后六位
    cout << "Integer division : 9/5 = " << 9 / 5 << endl; //整數(shù)相除結(jié)果取出整數(shù)部分
    cout << "Float division : 9.0/5.0 = " << 9.0 / 5.0 << endl;
    cout << "Mixed division : 9.0/5 = " << 9.0 / 5 << endl; //混合類型
    cout << "Mixed division : 9/5.0 = " << 9 / 5.0 << endl; //混合類型  浮點型精度高于整型，提升精度為浮點型
    cout << "Double division : 1e7 / 9.0 = " << 1e7 / 9.0 << endl;              //都當成double類型來處理(精度高) 一般定義浮點數(shù)用double，編譯器默認當成double處理，除非你強制float
    cout << "FLoat constance division : 1e7f / 9.0f = " << 1e7f / 9.0f << endl; //都當成float類型來處理
    return 0;
}

#include <iostream>
int main(void)
{
    using namespace std;
    const int pounds_per_stone = 14; //聲明整型類型常量   14榜(pounds)=1英石(stone)
    cout << "Enter your weight in pounds: ";
    int lbs;
    cin >> lbs;
    int stone = lbs / pounds_per_stone;
    int pounds = lbs % pounds_per_stone;
    cout << lbs << "pounds = " << stone << " stone, " << pounds << " pounds." << endl;
    return 0;
}

#include <iostream>
int main(void)
{
    using namespace std;
    cout.setf(ios_base::fixed, ios_base::floatfield);
    float tree = 3;
    int guess(3.9832); // C++特有賦值方式,這里取出小數(shù)的整數(shù)部分
    int debt = 6.2E22; //超過了整型的取值范圍,結(jié)果不確定，對于int（32位 -2^31---2^31-1）太大了
    cout << "tree = " << tree << endl;
    cout << "guess = " << guess << endl;
    cout << "debt = " << debt << endl;
    return 0;
}

 
#include <iostream>
int main(void)
{
    using namespace std;
    int auks, bats, coots;
    auks = 19.99 + 11.99;            //計算機用double類型相加計算再轉(zhuǎn)換為整型，結(jié)果取整=31
    bats = (int)19.99 + (int)11.99;  // C語言格式
    coots = int(19.99) + int(11.99); // C++語言格式
    cout << "auks = " << auks << endl;
    cout << "bats = " << auks << endl;
    cout << "coots = " << auks << endl;
    char ch = 'Z';
    cout << "The code for " << ch << " is " << int(ch) << endl;
    cout << static_cast<int>(ch) << endl; //強制類型轉(zhuǎn)換
    return 0;
}