The parseInt() method of Java Integer class parses the CharSequence argument as a signed decimal integer.
The second parameter parses the string argument as a signed integer in the radix specified by the second argument.
The third parameter parses the CharSequence argument as a signed int in the specified radix, beginning at the specified beginIndex and extending to endIndex -1.
Syntax
- public static int parseInt(String s) throws NumberFormatException
- public static int parseInt(String s, int radix) throws NumberFormatException
- public static int parseInt(CharSequence s, int beginIndex, int endIndex, int radix) throws NumberFormatException
Parameters
s- a String containing the int representation to be parsed.
radix- the radix to be used while parsing s.
beginIndex- the beginning index.
endIndex- the ending index.
Return Value
This method returns an integer value represented by the argument in decimal or by the subsequence in the specified radix.
Throws
This method throws:
NumberFormatException– if the String does not contain a parsable int.
IndexOutOfBoundsException- if beginIndex is negative, or if beginIndex is greater than endIndex or if endIndex is greater than s.length().
NumberFormatException- if the CharSequence does not contain a parsable int in the specified radix, or if radix is either smaller than Character.MAX_RADIX or larger than Character.MAX_RADIX.
Example 1
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public class JavaIntegerParseIntExample1 { public static void main(String[] args) { String s="123"; //parses the CharSequence argument as a signed decimal integer int val=Integer.parseInt(s); System.out.println(val); } } |
Output
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123 |
Example 2
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public class JavaIntegerParseIntExample2 { public static void main(String[] args) { String s="123"; int radix=9; //parses the string argument as a signed integer in the radix specified by the second argument int val=Integer.parseInt(s,radix); System.out.println(val); } } |
Output
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102 |
Example 3
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public class JavaIntegerParseIntExample3 { public static void main(String[] args) { String s="123"; //radix should be smaller than Character.MAX_RADIX i.e. 36 else it will give you an error int radix=37; //parses the string argument as a signed integer in the radix specified by the second argument int val=Integer.parseInt(s,radix); System.out.println(val); } } |
Output
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Exception in thread "main" java.lang.NumberFormatException: radix 37 greater than Character.MAX_RADIX at java.lang.Integer.parseInt(Integer.java:551) at com.TutorialAndExample.JavaIntegerParseIntExample3.main(JavaIntegerParseIntExample3.java:9) |
Example 4
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public class JavaIntegerParseIntExample4 { public static void main(String[] args) { //give NumberFormatException if the String does not contain a parsable int String s=null; //radix should be smaller than Character.MAX_RADIX i.e. 36 else it will give you an error int radix=37; /*It parses the CharSequence argument as a signed as a signed int in the specified radix, beginning at the specified beginIndex and extending to endIndex -1.*/ int val=Integer.parseInt(s,radix); System.out.println(val); } } |
Output
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Exception in thread "main" java.lang.NumberFormatException: null at java.lang.Integer.parseInt(Integer.java:542) at com.TutorialAndExample.JavaIntegerParseIntExample4.main(JavaIntegerParseIntExample4.java:10) |