What are the different ways in which DecimalFormat can be used?

DecimalFormat is a Java class used for formatting numbers, it can format numbers into specific patterns based on the specified format. Here are some common usages of DecimalFormat:

1. Create a DecimalFormat object.

DecimalFormat df = new DecimalFormat("#,###.00"); // 创建一个带有千位分隔符和小数点的格式

1. Format numbers.

double number = 12345.6789;
String formattedNumber = df.format(number);
System.out.println(formattedNumber); // 输出：12,345.68

1. Parse a string into a number.

String strNumber = "12,345.67";
double parsedNumber = df.parse(strNumber).doubleValue();
System.out.println(parsedNumber); // 输出：12345.67

1. Customize the format:

df.applyPattern("0.###"); // 设置一个不带千位分隔符的小数格式

1. Set currency format:

DecimalFormat currencyFormat = new DecimalFormat("¤#,###.00"); // 创建一个带有货币符号的格式

1. localization settings

df.setDecimalFormatSymbols(new DecimalFormatSymbols(Locale.US)); // 设置使用美国的格式化规则

1. Set the maximum and minimum values:

df.setMaximumFractionDigits(3); // 设置小数点后最多保留3位小数
df.setMinimumIntegerDigits(5); // 设置至少保留5位整数

These are some common uses of DecimalFormat, which allow for formatting and parsing numbers using these methods.