使用正确的小数位数格式化数字

num = 3.141592653589793
formatted_num = round(num, 2)
print(formatted_num)  # 输出：3.14

let num = 3.141592653589793;
let formattedNum = num.toFixed(2);
console.log(formattedNum);  // 输出："3.14"

double num = 3.141592653589793;
DecimalFormat decimalFormat = new DecimalFormat("#.##");
String formattedNum = decimalFormat.format(num);
System.out.println(formattedNum);  // 输出："3.14"

$num = 3.141592653589793;
$formattedNum = number_format($num, 2);
echo $formattedNum;  // 输出："3.14"