parseInt is the way to go. The Integer documentation says
Use parseInt(String) to convert a string to a int primitive, or use valueOf(String) to convert a string to an Integer object.
parseInt is likely to cover a lot of edge cases that you haven't considered with your own code. It has been well tested in production by a lot of users.
Reddit
reddit.com › r/learnjava › integer.valueof() and parseint()
r/learnjava on Reddit: Integer.valueOf() and parseint()
September 14, 2023 -
Hello, i have started learning java recently by mooc. But during this course, it uses Integer.valueOf while taking integer inputs, I use same way but whenever i do it intellij suggests me parseint(). And I wonder if it is better to use parseint?
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Integer.parseInt() returns a primitive. valueOf() returns an Integer object. Call the one that matches the return type you need and avoid autoboxing/unboxing.
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Tutorialspoint
tutorialspoint.com › home › java/lang › java integer parseint method
Java Integer parseInt Method
September 1, 2008 - The Java Integer parseInt(String s) method parses the string argument s as a signed decimal integer.
Integer.parseInt is best way to convert String to Int in Java? - Stack Overflow
We normally use Integer.parseInt method for String to Integer conversion in JAVA, but when I check the implementation of parseInt method it goes way deep that I think initially. Below I m sharing how More on stackoverflow.com
Integer.valueOf() and parseint()
Integer.parseInt() returns a primitive. valueOf() returns an Integer object. Call the one that matches the return type you need and avoid autoboxing/unboxing. More on reddit.com
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September 14, 2023'Undeclared method' error for parseInt(), even those its part of the java.lang package(BlueJ)
No, parseInt are methods of the java.lang.Integer class, not the package. While the package java.lang is imported by default, the methods of java.lang.Integer are not statically imported by default. You can write Integer.parseInt(...), because Integer is part of the java.lang package, which is imported by default. More on reddit.com
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August 20, 2022Java throws NumberFormatException with "9646324351"
The maximum value for an integer is 2,147,483, 647. Try using Long.parseLong(). More on reddit.com
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April 7, 2022Videos
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How to Convert String to Integer Java - Full Tutorial {2025} - YouTube
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parseInt Java Tutorial - String to Integer #56 - YouTube
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4 Ways to Convert String to Int in Java
BeginnersBook
beginnersbook.com › 2022 › 10 › java-integer-parseintmethod
Java Integer parseInt()Method
October 27, 2022 - Java Integer parseInt() method returns int value after parsing the given string using the specified radix.
Tutorialspoint
tutorialspoint.com › home › java › java integer parsing
Java Integer Parsing
September 1, 2008 - ... parseInt(int i) − This returns an integer, given a string representation of decimal, binary, octal, or hexadecimal (radix equals 10, 2, 8, or 16 respectively) numbers as input.
Oracle
docs.oracle.com › javase › 8 › docs › api › java › lang › Integer.html
Integer (Java Platform SE 8 )
October 20, 2025 - The characters in the string must all be decimal digits, except that the first character may be an ASCII minus sign '-' ('\u002D') to indicate a negative value or an ASCII plus sign '+' ('\u002B') to indicate a positive value. The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseInt(java.lang.String, int) method.
TutorialsPoint
tutorialspoint.com › what-does-integer-parseint-method-do-in-java
What does Integer.parseInt() method do in Java?
July 30, 2019 - JavaObject Oriented ProgrammingProgramming · This is a static method of the class named Integer it accepts an integer parameter and Parses it as a signed decimal integer. Live Demo · public class IntegerDemo { public static void main(String[] args) { // parses the string argument int a = ...
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parseInt is the way to go. The Integer documentation says
Use parseInt(String) to convert a string to a int primitive, or use valueOf(String) to convert a string to an Integer object.
parseInt is likely to cover a lot of edge cases that you haven't considered with your own code. It has been well tested in production by a lot of users.
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I invite you to look at the source code of the parseInt function. Your naïve function is faster, but it also does way less. Edge cases, such as the number being to large to fit into an int or not even being a number at all, will produce undetectable bogus results with your simple function.
It is better to just trust that the language designers have done their job and have produced a reasonably fast implementation of parsing integers. Real optimization is probably elsewhere.
Scaler
scaler.com › home › topics › parseint() in java
parseInt() in Java - Scaler Topics
May 8, 2024 - It is used in Java for converting a string value to an integer by using the method parseInt().
vteams
vteams.com › blog › use-of-parseint-java-programming
Learn the Basics & Ins-And-Outs of PARSEint Java Programming
February 23, 2024 - In the following article you will ... the PARSEInt while coding. Basically, PARSE int Java programming is a method that converts a string to an integer....
CodeAhoy
codeahoy.com › java › Convert-String-To-Int
Java String to int with examples | CodeAhoy
October 22, 2019 - Learn how to convert String to int or Integer in Java using Integer.parseInt() or Integer.valueOf() with examples.
GeeksforGeeks
geeksforgeeks.org › java › integer-valueof-vs-integer-parseint-with-examples
Integer.valueOf() vs Integer.parseInt() with Examples - GeeksforGeeks
July 11, 2025 - It takes a valid string as a parameter and parses it into primitive data type int. It only accepts String as a parameter and on passing values of any other data type, it produces an error due to incompatible types.
Oracle
docs.oracle.com › en › java › javase › 21 › docs › api › java.base › java › lang › Integer.html
Integer (Java SE 21 & JDK 21)
January 20, 2026 - ... Deprecated, for removal: This API element is subject to removal in a future version. It is rarely appropriate to use this constructor. Use parseInt(String) to convert a string to a int primitive, or use valueOf(String) to convert a string to an Integer object.
Coderanch
coderanch.com › t › 615414 › java › choosing-Integer-decode-String-str
Why choosing to use Integer.decode(String str) over ...
Well, if this helps you decide... in the implementation, the decode() method calls the parseInt() method. The decode() method, decodes the 0x # etc., and then calls parseInt() with the decoded radix. Henry · Books: Java Threads, 3rd Edition, Jini in a Nutshell, and Java Gems (contributor)
Demmel
demmel.com › joc › help › JavaDocumentation › java › lang › Integer › parseInt.htm
Method java.lang.Integer.parseInt
The characters in the string must all be decimal digits, except that the first character may be an ASCII minus sign '-' ('\u002d') to indicate a negative value. The resulting integer value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseInt(String, ...
Coderanch
coderanch.com › t › 377888 › java › intValue-ParseInt
intValue Vs ParseInt (Java in General forum at Coderanch)
September 21, 2005 - Originally posted by Mahesh Pinnamaneni: my doubt is as we can achive convertion from the static parseInt why the SUN has introduced this intValue(). where exactly can we use this. pls help me. What if you don't have a String object? What if the object that was given to you is a Integer object? How would you get the int value back? On a side note, the intValue() method is part of the Number interface, this means that you can call it on a Integer, Float, Double, Long, objects and get an int value back. Henry · Books: Java Threads, 3rd Edition, Jini in a Nutshell, and Java Gems (contributor)
GeeksforGeeks
geeksforgeeks.org › java › wrapper-classes-java
Wrapper Classes in Java - GeeksforGeeks
Explanation: Here, the primitive int value is automatically converted into an Integer object by Java.
Published January 25, 2026
Quarkus
quarkus.io › blog › k8s-style-CEL-with-quarkus-chicory
A Go CEL Policy Engine in Java, with Quarkus Chicory - Quarkus
1 week ago - With such potential in our hands, we chose the popular Google CEL, a Go library/API adopted by several Go operators, and decided to integrate it in our application. Creating the application is straightforward using the Quarkus Maven plugin. Note that Quarkus 3.x requires Java 17 or higher (we used Java 21 for this example):
W3Schools
w3schools.com › js › js_number_methods.asp
W3Schools.com
parseInt() parses a string and returns a whole number. Spaces are allowed.
Epoch Converter
epochconverter.com
Epoch Converter - Unix Timestamp Converter
Literally speaking, the epoch is Unix time 0 (midnight 1/1/1970), but 'epoch' is often used as a synonym for Unix time. Some systems store epoch dates as a signed 32-bit integer, which might cause problems on January 19, 2038 (known as the Year 2038 problem or Y2038).
Baeldung
baeldung.com › home › java › java numbers › difference between parseint() and valueof() in java
Difference Between parseInt() and valueOf() in Java | Baeldung
January 8, 2024 - The first variant of parseInt() accepts a String as a parameter and returns the primitive data type int. It throws NumberFormatException when it cannot convert the String to an integer.