1, alignment
//by 鸟哥 qq1833183060
#include <iomanip>
#include <iostream>
int main(void) {
//1、方式1
//左对齐
std::cout <<std::left<< std::setw(20) << -123.456 << "|" << std::endl;
//两端对齐
std::cout <<std::internal<<std::setw(20) << -123.456 << "|" << std::endl;
std::cout <<std::internal<<std::setw(20) << "hello world!" << "|" << std::endl;
//右对齐
std::cout <<std::right<< std::setw(20) << -123.456 << "|" << std::endl;
//2、方式2
//左对齐
std::cout.flags(std::ios::left);
std::cout <<std::setw(20) << -123.456 << "|" << std::endl;
//两端对齐
std::cout.flags(std::ios::internal);
std::cout <<std::setw(20) << -123.456 << "|" << std::endl;
std::cout <<std::setw(20) << "hello world!" << "|" << std::endl;
//右对齐
std::cout.flags(std::ios::right);
std::cout <<std::right<< std::setw(20) << -123.456 << "|" << std::endl;
return 0;
}operation result:
-123.456 | - 123.456| hello world!| -123.456| -123.456 | - 123.456| hello world!| -123.456|
2, display an integer
//by 鸟哥 qq1833183060
#include <iomanip>
#include <iostream>
using namespace std;
int main(void) {
cout<<showpos;//在十进制数字前显示＋号
cout<<uppercase;//将字母显示为大写
cout << hex << setw(4) << 315 << setw(12) << -315 << endl;
cout << dec << setw(4) << 315 << setw(12) << -315 << endl;
cout << oct << setw(4) << 315 << setw(12) << -315 << endl;
cout<<noshowpos;//取消showpos标记
cout<<nouppercase;//取消uppercase标记
cout << hex << setw(4) << 315 << setw(12) << -315 << endl;
cout << dec << setw(4) << 315 << setw(12) << -315 << endl;
cout << oct << setw(4) << 315 << setw(12) << -315 << endl;
return 0;
}operation result:
13B FFFFFEC5 +315 -315 473 37777777305 13b fffffec5 315 -315 473 37777777305
3, display binary prefixes
//by 鸟哥 qq1833183060
#include <iomanip>
#include <iostream>
using namespace std;
int main(void) {
int n=66;
int w=6;
cout << showbase << setw(w) << hex << n<< setw(w) << oct << n << dec<<setw(w)<<n<<endl;
cout << noshowbase << setw(w) << hex << n << setw(w) << oct << n << dec<<setw(w)<<n<< endl;
return 0;
}operation result:
0x42 0102 66 42 102 66
4, shown float
//by 鸟哥 qq1833183060
#include <iomanip>
#include <iostream>
using namespace std;
int main(void) {
double f=31.415;
for(int i=0;i<6;i++){
cout<<fixed;
cout << setprecision(i) << f << endl;
cout<<scientific;
cout << setprecision(i) << f << endl;
}
return 0;
}operation result:
31 3e +01 31.4 3.1e+01 31.41 3.14e + 01 31.415 3.141e+01 31.4150 3.1415e+01 31.41500 3.14150e+01
