Java Program To Convert String to int or Integer


Learn How To Convert String to int in Java. Converting String to integer in java can be done in 3 ways as following. 1) Integer.parseInt(String s) method 2) Integer. valueOf(String s) method 3) Integer Constructor

How to convert a String to Integer wrapper class or int primitive type?
Differences between Integer.parseInt(String s) and Integer.valueOf(String s)?

Converting Java String to Integer:

In some cases, we may be getting numbers in format of String so need to convert to integer for our process.

Eg. Given string like "9876" than result would be 9876 int type.

We can perform Java String to Integer operation in 3 ways. 
1) Integer.parseInt(String s) method  
2) Integer. valueOf(String s)  method 
3) Integer Constructor

Convert Java String to Integer or int

1) Integer.parseInt(String s) method:

Integer is in package of "java.lang.Integer" and wraps primitive type to Object representation.

Method parseInt internally does read character by character using charAt() method in String class and convert it into int format.
parseInt(String number) returns int primitive type.

Integer.parseInt Example

package com.java.w3schools.core.initializer;

public class StringtoInteger01 {

    public static void main(String[] args) {

        // String to integer

        int number = Integer.parseInt("1234");
        System.out.println("Number :: " + number);


Number :: 1234

Eg. Integer.parseInt("ABC123");

2) Integer.valueOf(String s)  method:

Integer class has a method valueOf declared as Static. So directly can access method with class name.

valueOf() method internally operates

a) invokes parseInt() methods.
b) In addition, operates on static variables of IntegerCache class which holds values on Integer[] array.
c) This returns Integer wrapper class object.

Integer.valueOf() is equivalent to new Integer(Integer.parseInt(s)).

For both methods , We should input only numerics in format of String. Apart from numerics, if give alphabetics will result in "NumberFormatException"
    number = Integer.valueOf("-4567");

    System.out.println("number :: "+number);


number :: -4567

3) Integer Constructor:

By passing string to the Integer constructor which  has parameter String literal. internally uses parseInt method.


new Integer(String s);

    number = new Integer("9999");

    System.out.println("Constructor number : "+number);


Constructor number : 9999



About Us

Author: Venkatesh - I love to learn and share the technical stuff.

accumulo,1,ActiveMQ,2,Adsense,1,API,37,ArrayList,18,Arrays,24,Bean Creation,3,Bean Scopes,1,BiConsumer,1,Blogger Tips,1,Books,1,C Programming,1,Collection,8,Collections,37,Collector,1,Command Line,1,Comparator,1,Compile Errors,1,Configurations,7,Constants,1,Control Statements,8,Conversions,6,Core Java,149,Corona India,1,Create,2,CSS,1,Date,3,Date Time API,38,Dictionary,1,Difference,2,Download,1,Eclipse,3,Efficiently,1,Error,1,Errors,1,Exceptions,8,Fast,1,Files,17,Float,1,Font,1,Form,1,Freshers,1,Function,3,Functional Interface,2,Garbage Collector,1,Generics,4,Git,9,Grant,1,Grep,1,HashMap,2,HomeBrew,2,HTML,2,HttpClient,2,Immutable,1,Installation,1,Interview Questions,6,Iterate,2,Jackson API,3,Java,32,Java 10,1,Java 11,6,Java 12,5,Java 13,2,Java 14,2,Java 8,128,Java 8 Difference,2,Java 8 Stream Conversions,4,java 8 Stream Examples,12,Java 9,1,Java Conversions,14,Java Design Patterns,1,Java Files,1,Java Program,3,Java Programs,114,Java Spark,1,java.lang,4,java.util. function,1,JavaScript,1,jQuery,1,Kotlin,11,Kotlin Conversions,6,Kotlin Programs,10,Lambda,2,lang,29,Leap Year,1,live updates,1,LocalDate,1,Logging,1,Mac OS,3,Math,1,Matrix,6,Maven,1,Method References,1,Mockito,1,MongoDB,3,New Features,1,Operations,1,Optional,6,Oracle,5,Oracle 18C,1,Partition,1,Patterns,1,Programs,1,Property,1,Python,2,Quarkus,1,Read,1,Real Time,1,Recursion,2,Remove,2,Rest API,1,Schedules,1,Serialization,1,Servlet,2,Sort,1,Sorting Techniques,8,Spring,2,Spring Boot,23,Spring Email,1,Spring MVC,1,Streams,31,String,61,String Programs,28,String Revese,1,StringBuilder,1,Swing,1,System,1,Tags,1,Threads,11,Tomcat,1,Tomcat 8,1,Troubleshoot,26,Unix,3,Updates,3,util,5,While Loop,1,
JavaProgramTo.com: Java Program To Convert String to int or Integer
Java Program To Convert String to int or Integer
Learn How To Convert String to int in Java. Converting String to integer in java can be done in 3 ways as following. 1) Integer.parseInt(String s) method 2) Integer. valueOf(String s) method 3) Integer Constructor
Loaded All Posts Not found any posts VIEW ALL Readmore Reply Cancel reply Delete By Home PAGES POSTS View All RECOMMENDED FOR YOU LABEL ARCHIVE SEARCH ALL POSTS Not found any post match with your request Back Home Sunday Monday Tuesday Wednesday Thursday Friday Saturday Sun Mon Tue Wed Thu Fri Sat January February March April May June July August September October November December Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec just now 1 minute ago $$1$$ minutes ago 1 hour ago $$1$$ hours ago Yesterday $$1$$ days ago $$1$$ weeks ago more than 5 weeks ago Followers Follow THIS PREMIUM CONTENT IS LOCKED STEP 1: Share to a social network STEP 2: Click the link on your social network Copy All Code Select All Code All codes were copied to your clipboard Can not copy the codes / texts, please press [CTRL]+[C] (or CMD+C with Mac) to copy Table of Content