Java 如何将答案四舍五入到小数点后两位
我有一个简单的数学例子,加法,减法,除法和乘法,使用变量作为double,如果我用小数加减法,除法或乘法,答案应该在小数点后两位Java 如何将答案四舍五入到小数点后两位,java,Java,我有一个简单的数学例子,加法,减法,除法和乘法,使用变量作为double,如果我用小数加减法,除法或乘法,答案应该在小数点后两位 private void jButton_addActionPerformed(java.awt.event.ActionEvent evt) { double First = Double.parseDouble(jTextField1.get
private void jButton_addActionPerformed(java.awt.event.ActionEvent
evt) {
double First = Double.parseDouble(jTextField1.getText());
// Read the Second number
double Second = Double.parseDouble(jTextField2.getText());
// Set the Result
double Result = First + Second;
jLabel4.setText(String.valueOf(Result));
}
private void jButton_substractActionPerformed
(java.awt.event.ActionEvent evt)
{
double First = Double.parseDouble(jTextField1.getText());
// Read the Second number
double Second = Double.parseDouble(jTextField2.getText());
// Set the Result
double Result = First - Second;
jLabel4.setText(String.valueOf(Result));
}
private void jButton_MultiplyActionPerformed
(java.awt.event.ActionEvent evt)
{
double First = Double.parseDouble(jTextField1.getText());
// Read the Second number
double Second = Double.parseDouble(jTextField2.getText());
// Set the Result
double Result = First * Second;
jLabel4.setText(String.valueOf(Result));
}
private void jButton_divideActionPerformed(java.awt.event.ActionEvent
evt) {
double First = Double.parseDouble(jTextField1.getText());
// Read the Second number
double Second = Double.parseDouble(jTextField2.getText());
// Set the Result
double Result = First / Second;
jLabel4.setText(String.valueOf(Result));
}
如何将结果四舍五入到两个小数点,如12.38而不是12.379999
double round = Math.round(number * 100.0) / 100.0;
其中number
是您的十进制数
要分解它-
double number = 3.14159;
number = Math.round(number * 100);
number = number/100;
输出将为3.14使用setRoundingMode告诉它您需要多少小数点。堆栈溢出中可能存在的重复问题应为您提供解决方案。