Java - Convert a String to int

In Java, to convert a String to int, you can use Integer.parseInt() or Integer.valueOf().

Example of Integer.parseInt()

String nombre_str = "22"; 
int number = Integer.parseInt(nombre_str); 
System.out.println(number); 

Runtime:

22

Example of Integer.valueOf()

The Integer.valueOf() will return an object Integer.

String nombre_s="22"; 
int number = Integer.valueOf(nombre_s); 
System.out.println(number); 

Execution

22

In case the string is not accepted because it contains an alphabetic character, for example, a NumberFormatException will be triggered.

String nombre_s="9Ab"; 
int number = Integer.parseInt(nombre_s); 
System.out.println(number); 

Output:

Exception in thread "main" java.lang.NumberFormatException: For input string: "9Ab"
 at java.lang.NumberFormatException.forInputString(Unknown Source)
 at java.lang.Integer.parseInt(Unknown Source)
 at java.lang.Integer.valueOf(Unknown Source)

Resources:
http://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html#valueOf(java.lang.String, int)
http://docs.oracle.com/javase/7/docs/api/java/lang/Integer.html#parseInt(java.lang.String)