Strings in Java string to int (go)

Source: Internet
Author: User

Strings in Java string to int string-int
  
S= "12345";
int i;
The first method: I=integer.parseint (s);
The second method: I=integer.valueof (s). Intvalue ();
What is the difference between these two methods? Does it work the same? Are they interchangeable under any circumstances?
  
String int
  
int i=12345;
String s= "";
The first method: s=i+ "";
The second method: S=string.valueof (i);
What is the difference between these two methods? Does it work the same? Are they interchangeable under any circumstances?
  
  
Here's the answer:
  
  
The first method: s=i+ ""; produces two string objects
The second method: S=string.valueof (i); Use static methods of the string class directly, producing only one object
  
The first method: I=integer.parseint (s);//Use static methods directly, do not produce extra objects, but throw exceptions
The second method: I=integer.valueof (s). Intvalue ();//integer.valueof (s) equals the new Integer (Integer.parseint (s)) and throws an exception, but produces an extra object

  
--------------------------------------------------------------------
1 How do I convert string strings to integer int?
  
A. There are two methods:
  
1). int i = Integer.parseint ([String]); Or
i = Integer.parseint ([string],[int radix]);
  
2). int i = integer.valueof (my_str). Intvalue ();
  
Note: The string is converted to Double, Float, and Long in a similar way.
  
2 How do I convert an integer int to a string string?
  
A. There are three ways:
  
1.) String s = string.valueof (i);
  
2.) String s = integer.tostring (i);
  
3.) String s = "" + I;
  
Note: Double, Float, Long turn into a string in a similar way.
  
  
  
Java Data type conversions
  
This is an example of the conversion of data numbers in Java. For everyone to learn
  
Package Shenmixiaozhu;
Import Java.sql.Date;
public class Typechange {
Public Typechange () {
}
Change the string type to the int type
public static int Stringtoint (String intstr)
{
Integer integer;
Integer = integer.valueof (INTSTR);
return Integer.intvalue ();
}
change int type to the string type
public static String inttostring (int value)
{
Integer integer = new integer (value);
return integer.tostring ();
}
Change the string type to the float type
public static float Stringtofloat (String floatstr)
{
Float floatee;
Floatee = float.valueof (FLOATSTR);
return Floatee.floatvalue ();
}
Change the float type to the string type
public static String floattostring (float value)
{
float floatee = new float (value);
return floatee.tostring ();
}
Change the string type to the Sqldate type
public static Java.sql.Date stringtodate (String datestr)
{
Return java.sql.Date.valueOf (DATESTR);
}
Change the Sqldate type to the string type
public static String datetostring (Java.sql.Date datee)
{
return datee.tostring ();
}
  
public static void Main (string[] args)
{
Java.sql.Date Day;
Day = Typechange.stringtodate ("2003-11-3");
String strday = typechange.datetostring (day);
System.out.println (Strday);
}
  
}
  

Strings in Java string to int (go)

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