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There are two ways to retain two decimal places in output in C: 1. Use std::fixed and std::setprecision to control the output stream formatting, such as: cout << fixed << setprecision (2) << value; 2. Use std::to_string and std::substr to convert the number to a string and extract the number of decimal places, such as: string result = str.substr(0, str.find('. ') 3);
How to retain two decimal places in C output?
There are two ways to retain two decimal places in output in C:
1. Use std::fixed and std::setprecision
This method is implemented by controlling the formatting of the output stream.
<code class="cpp">#include <iostream> #include <iomanip> using namespace std; int main() { double value = 123.456789; // 设置保留两位小数 cout << fixed << setprecision(2) << value << endl; return 0; }</code>
Output:
<code>123.46</code>
2. Using std::to_string and std::substr
This method involves converting a number to a string, Then extract the required number of decimal places.
#include
#include
using namespace std;
int main() {
double value = 123.456789;
// 转换为字符串
string str = to_string(value);
// 提取两位小数
string result = str.substr(0, str.find('.') + 3);
cout << result << endl;
return 0;
}
Output:
<code>123.46</code>
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