How to convert a String to int in Java?

Introduction

In this post, we will learn to convert String to int primitive data type. Java provides the Integer wrapper class to convert a String to int.

Integer.parseInt(String)

String numberString = "134";
int number = Integer.parseInt(numberString );
System.out.println(number);

Output: 134

Integer.valueOf(String)

String numberString = "134";

int number = Integer.valueOf(numberString );

System.out.println(number);

Output: 134

The following code will throw NumberFormatException

//134a cannot be converted to Integer
String numberString = "134a";
int number = Integer.valueOf(numberString );
System.out.println(number);

Exception in thread "main" java.lang.NumberFormatException: For input string: "134a"
at java.lang.NumberFormatException.forInputString(Unknown Source)
at java.lang.Integer.parseInt(Unknown Source)
at java.lang.Integer.valueOf(Unknown Source)
at StringExample.main(StringExample.java:6)