有几种方法可以将String转换为long:

1)

long l = Long.parseLong("200"); 

String numberAsString = "1234";
long number = Long.valueOf(numberAsString).longValue();

String numberAsString = "1234";
Long longObject = new Long(numberAsString);
long number = longObject.longValue();

我们可以缩短为:

String numberAsString = "1234";
long number = new Long(numberAsString).longValue();

或者只是

long number = new Long("1234").longValue();

使用十进制格式:

String numberAsString = "1234";
DecimalFormat decimalFormat = new DecimalFormat("#");
try {
    long number = decimalFormat.parse(numberAsString).longValue();
    System.out.println("The number is: " + number);
} catch (ParseException e) {
    System.out.println(numberAsString + " is not a valid number.");
}

要将String转换为Long(对象)，请使用Long。返回对象的值(字符串).longValue ();

看到链接

这很简单，使用 长。返回对象的值(字符串);

例如:

String s;
long l;

Scanner sc=new Scanner(System.in);
s=sc.next();
l=Long.valueOf(s);
System.out.print(l);

你做完了! !

长。valueOf(String s) -显然，如果在代码中可能出现非数字，则必须采取适当的保护措施。

public class StringToLong {

   public static void main (String[] args) {

      // String s = "fred";    // do this if you want an exception

      String s = "100";

      try {
         long l = Long.parseLong(s);
         System.out.println("long l = " + l);
      } catch (NumberFormatException nfe) {
         System.out.println("NumberFormatException: " + nfe.getMessage());
      }

   }
}

有几种方法可以将String转换为long:

1)

long l = Long.parseLong("200"); 

String numberAsString = "1234";
long number = Long.valueOf(numberAsString).longValue();

String numberAsString = "1234";
Long longObject = new Long(numberAsString);
long number = longObject.longValue();

我们可以缩短为:

String numberAsString = "1234";
long number = new Long(numberAsString).longValue();

或者只是

long number = new Long("1234").longValue();

使用十进制格式:

String numberAsString = "1234";
DecimalFormat decimalFormat = new DecimalFormat("#");
try {
    long number = decimalFormat.parse(numberAsString).longValue();
    System.out.println("The number is: " + number);
} catch (ParseException e) {
    System.out.println(numberAsString + " is not a valid number.");
}