C + + cout statement format control output __c++

Brief Introduction

In the Prinf () of the C language, the control output can be formatted. But the cout in C + + should be how to form the control output.

SETW (n) to control the preset width. SETW () only acts on the output immediately following it. If the input exceeds the length of the SETW () setting, output is based on the actual length. The default right alignment.

Setfill (char c), which is populated with the set character C if the width is already unused in the preset width.

Left and right, change the alignment. The default is right alignment.

fixed, using decimal notation

Setprecision (n) controls the precision of the output stream to display floating-point numbers, that is, the number of digits after the decimal point.

Scientific, use the scientific counting method.

Showpos, plus a plus sign before a positive number.

Example

#include <iostream>
#include <iomanip>
#include <vector>
using namespace std;
void Main ()
{
	double x[2][4] = {{1.2123, 0.1, 0.00021, 43.1}, {32.1, 0.4, 0.54302, 0.0003}};
	for (int i = 0; i < 2; i++) {for
		(int j = 0; J < 4; J +) {
			cout << setw (8) << setprecision (5) ;< fixed << left << Setfill (' 0 ') << x[i][j] << "T";
		cout << Endl;
	}

Results:

#include <iostream>
#include <iomanip>
#include <vector>
using namespace std;
void Main ()
{
	int x[2][4] = {1, 0, -1234, {}, {9871, $, 0}};
	for (int i = 0; i < 2; i++) {for
		(int j = 0; J < 4; J +) {
			cout << setw (8) << setprecision (5) & lt;< fixed << left <<  x[i][j] << "T";
		}
		cout << Endl;
	}

Visible, the data is aligned.

Note: Sometimes, when the N value in SETW (n) is smaller, the data will appear misaligned, and then the N value can be adjusted.

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