string and int in Java convert each other

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 integer int into 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.

String int  

int i=12345;
String s= "";
The first method: s=i+ "";
Another method: S=string.valueof (i);
What is the difference between these two methods? Does it work the same? Is it possible to be interchangeable under no circumstances?

String-int  

S= "12345";
int i;
The first method: I=integer.parseint (s);
Another method: I=integer.valueof (s). Intvalue ();
What is the difference between these two methods? Does it work the same? Is it possible to be interchangeable under no circumstances?

Here's the answer:

The first method: s=i+ ""; produces two string objects
Another method: S=string.valueof (i); A static method that directly uses the string class to produce only one object

The first method: I=integer.parseint (s);//Use static methods directly, do not produce extra objects, but throw exceptions
Another method: I=integer.valueof (s). Intvalue ();//integer.valueof (s) equals the new Integer (Integer.parseint (s)), and also throws

Exception, but produces more than one object

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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 integer int into 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

Keyword type conversions

This is a sample, that is, the conversion of data numbers in Java. For everyone to learn

Package cn.com.lwkj.erts.register;
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);
}

}
Data type conversion functions are often used in Java
Although all can be found in the Java API, tidy up to make a backup.

string and int in Java convert each other