Conversion in Java

String to Integer Conversions

source: https://www.geeksforgeeks.org/string-to-integer-in-java-parseint/

Difference between parseInt() and valueOf():

parseInt() parses the string and returns the primitive integer type. However, valueOf() returns an Integer object.

Note:

valueOf() uses parseInt() internally to convert to integer.

parseInt()

        int decimalExample = Integer.parseInt("20"); 
        int signedPositiveExample = Integer.parseInt("+20"); 
        int signedNegativeExample = Integer.parseInt("-20");

valueOf()

        int decimalExample = Integer.valueOf("20"); 
        int signedPositiveExample = Integer.valueOf("+20"); 
        int signedNegativeExample = Integer.valueOf("-20");

Integer to String Conversions

source: https://www.geeksforgeeks.org/different-ways-for-integer-to-string-conversions-in-java/

1.Convert using Integer.toString(int)

class GfG 
{ 
public static void main(String args[]) 
{ 
    int a = 1234; 
    int b = -1234; 
    String str1 = Integer.toString(a); 
    String str2 = Integer.toString(b); 
    System.out.println("String str1 = " + str1); 
    System.out.println("String str2 = " + str2); 
} 
}

1. Convert using String.valueOf(int)

class GfG 
{ 
public static void main(String args[]) 
{ 
    String str3 = String.valueOf(1234); 
    System.out.println("String str3 = " + str3); 
} 
}

3.Convert using Integer(int).toString()

class GfG 
{ 
public static void main(String args[]) 
{ 
    int d = 1234; 
    String str4 = new Integer(d).toString(); 
    System.out.println("String str4 = " + str4); 
} 
}

4.Convert using DecimalFormat

import java.text.DecimalFormat; 
class GfG 
{ 
public static void main(String args[]) 
{ 
    int e = 12345; 
    DecimalFormat df = new DecimalFormat("#"); 
    String str5 = df.format(e); 
    System.out.println(str5); 
} 
}

5.Convert using StringBuffer or StringBuilder

class GfG 
{ 
public static void main(String args[]) 
{ 
    String str6 = new StringBuffer().append(1234).toString(); 
    System.out.println("String str6 = " + str6); 
} 
}

StringBuilder

class GfG 
{ 
public static void main(String args[]) 
{ 
    String str7 = new StringBuilder().append(1234).toString(); 
    System.out.println("String str7 = " + str7); 
} 
}