➤ Sum of digits in a String
➤ Count No of Vowels String
➤ String Pattern Programs in Java
➤ Take String Input In Java
➤ Take Multiple String Input in Java
➤ How To Reverse a String In Java
➤ Remove Special Characters
➤ String – Remove Character
➤ String Palindrome In Java
➤ Sort String In Java
➤ How to Compare Strings In Java
➤ Second Occurrence of Character
➤ Replace nth Occurrence String
➤ Last Occurrence of Character
➤ Uppercase & Lowercase
➤ Java Check If Char is Uppercase
➤ Check If String is Uppercase
➤ Swap Characters in String Java
➤ Java String indexOf() Method
➤ How to Replace Dot in Java?
➤ How to Find Length of String
➤ Substring Method In Java
➤ Split Method In Java
Transform String To Int Java & Vice-Versa | Here we will discuss how to convert the string value to int, and how to convert int to string. The string is immutable which means cannot be changed once declared.
How To Transform String to Int Java
To convert string to int we can use the below two methods:-
1. Integer.valueOf()
2. Integer.parseInt()
The below Java program transforms a string into an int by using the Integer.parseInt() method. The Integer.parseInt() method throws NumberFormatException if the given string is not a number.
public class Main {
public static void main(String[] args) {
String string = "2356";
int value = 0;
try {
value = Integer.parseInt(string);
System.out.println("Integer value = " + value);
} catch (NumberFormatException e) {
System.out.println("Invalid String");
}
string = "4569h";
try {
value = Integer.parseInt(string);
System.out.println("Integer value = " + value);
} catch (NumberFormatException e) {
System.out.println("Invalid String");
}
}
}
Output:-
Integer value = 2356
Invalid String
To transform string to int we can also use the valueOf() method of Integer class. The valueOf() method internally calls Integer.parseInt() method and therefore it also throws NumberFormatException if the given string is not a number.
public class Main {
public static void main(String[] args) {
String string = "2356";
int value = 0;
try {
value = Integer.valueOf(string);
System.out.println("Integer value = " + value);
} catch (NumberFormatException e) {
System.out.println("Invalid String");
}
string = "4569h";
try {
value = Integer.valueOf(string);
System.out.println("Integer value = " + value);
} catch (NumberFormatException e) {
System.out.println("Invalid String");
}
}
}
Output:-
Integer value = 2356
Invalid String
How To Transform Int To String Java
Now let us see how to transfer int to string. There are many ways to do so as listed below:-
1. By using the toString() method of Integer class
2. By using the valueOf() method of String class
3. By using the DecimalFormat class
4. By Using the StringBuilder class
5. By using the StringBuffer class
Transform int to String in Java by using the toString() method of the Integer class
public class Main {
public static void main(String args[]) {
int num1 = 89456;
int num2 = -12365;
String string1 = Integer.toString(num1);
String string2 = Integer.toString(num2);
System.out.println("String str1 = " + string1);
System.out.println("String str2 = " + string2);
}
}
Output:-
String str1 = 89456
String str2 = -12365
Transform int to String in Java by using the valueOf() method of the String class
public class Main {
public static void main(String args[]) {
int num = 4165415;
String string1 = String.valueOf(num);
System.out.println("String = " + string1);
}
}
Output:-
String str = 4165415
Transform int to String in Java by using DecimalFormat class
import java.text.DecimalFormat;
public class Main {
public static void main(String args[]) {
int num = 456987;
DecimalFormat df = new DecimalFormat("#");
String string = df.format(num);
System.out.println(string);
}
}
Output:-
456987
Transform int to String in Java by using the StringBuilder class
public class Main {
public static void main(String args[]) {
int number = 1234;
StringBuilder sb = new StringBuilder();
sb.append(number);
// convert StringBuilder to String
String string = sb.toString();
System.out.println("String = " + string);
}
}
Output:-
String = 1234
Transform int to String in Java by using the StringBuffer class
public class Main {
public static void main(String args[]) {
int number = 15345;
StringBuffer sb = new StringBuffer();
sb.append(number);
// convert StringBuffer to String
String string = sb.toString();
System.out.println("String = " + string);
}
}
Output:-
String = 15345
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