We can convert Double to String in Java using the following methods: String.valueOf() method Double.toString() method Convert Double to String in Java using the String.valueOf() method There are multiple overloaded versions of the valueOf() method from the String class. We will use the one which accepts double. Example class Test { public static void main(String[] args)…
Read More Convert Double to String in JavaThere are cases when we get a String that is actually a double. To work with it, we need to convert it to a double data type. Let’s see how we can convert String to Double in Java. Convert Java String to Double with parseDouble() method In the below example, we use the parseDouble() static…
Read More Convert Java String to DoubleWe can convert Java Long to String using the following methods: String.valueOf() method Long.toString() method Convert Java Long to String using the String.valueOf() method There are multiple overloaded versions of the valueOf() method from the String class. We will use the one which accepts a long data type. Example class Test { public static void…
Read More Convert Java Long to StringWe often have to extract some text that is a number. To perform some operations on that number, we must first convert it to the appropriate data type. In this post, you will learn how to convert Java String to long. The parseLong() method in Java is a static method that can be used to…
Read More Convert Java String to LongNeed to remove a character from String in Java? You can do that by converting the String to a StringBuilder class and using the deleteCharAt() method that removes the character at a specified position. Example class Test { public static void main(String[] args) { String str = “Learn Java”; str = new StringBuilder(str).deleteCharAt(5).toString(); System.out.println(str); } }…
Read More Remove a Character from String in JavaWant to learn how to count character occurrences in Java String? Below is the program that uses a Map to store chars as keys and the number of occurrences as values. class Test { public static void main(String[] args) { String str = “moiujjmhrqdoasdsooqavvae”; Map<Character, Integer> map = new HashMap<>(); for (int i = 0;…
Read More Count Character occurrences in Java StringThere are multiple ways to convert a String to an array in Java. We can convert it to a char array or String array. Convert a String to a char Array The String class, a fundamental data type in Java, has the useful toCharArray() method that enables the conversion of a String to a char array.…
Read More Convert a String to an Array in JavaIn this post, you will learn to check if a String contains only digits in Java. We will cover two methods: Using the Character.isDigit() method Using the Integer.parseInt() method Check if a String contains only digits in Java using the Character.isDigit() method In this example, we use a for loop to iterate over the elements…
Read More Check if a String contains only digits in Javapublic class Test { public static void main(String[] args) { String str = “racecar”; System.out.println(str.equals(new StringBuilder(str).reverse().toString())); } } Output: true We can do the same with the StringBuffer class since it also has the reverse() method. Using the for loop public class Test { public static void main(String[] args) { String str = “racecar”;…
Read More Check if String is Palindrome in Javapublic class Test { public static void main(String[] args) { String str = “1849231”; try { Integer.parseInt(str); Float.parseFloat(str); Double.parseDouble(str); Long.parseLong(str); System.out.println(“No error occurred. String is numeric!”); } catch (NumberFormatException e) { System.out.println(“String is not numeric!”); } } } Output: No error occurred. String is numeric! And if we try to parse a String that…
Read More Check if String is Numeric in Javapublic class Test { public static void main(String[] args) { String str1 = “Learn Java Programming with alegrucoding.com”; String str2 = “Learn Java”; String str3 = “Simple Java Programming”; // check if str1 contains str2 if (str1.contains(str2)) { System.out.println(“str2 is present in str1”); } else { System.out.println(“str2 is not present in str1”); } // check…
Read More Check if a String Contains a Substring in Javapublic class Test { public static void main(String[] args) { String str = “Not null or empty String”; if (str == null || str.length() == 0) { System.out.println(“str is null or empty!”); } else { System.out.println(“str is not null or empty!”); } String str1 = null; if (str1 == null || str1.length() == 0) {…
Read More Check if String is Null or Empty in Javapublic class Test { public static void main(String[] args) { String str = “Learn Java with alegrucoding.com”; System.out.println(str.length()); } } Output: 32 Also, we can use the for loop to count characters in a String. public class Test { public static void main(String[] args) { int count = 0; String str = “Learn Java…
Read More Get the Length of a String in JavaOutput: Java Methods from the StringUtils class that we can use to get a substring from String in Java: import org.apache.commons.lang3.StringUtils; public class Test { public static void main(String[] args) { String str = “Hello, my name is Tom, and I live in USA”; String substringBefore = StringUtils.substringBefore(str, “,”); String substringAfter = StringUtils.substringAfter(str, “,”); String substringBetween = StringUtils.substringBetween(str,…
Read More Get Substring from String in Javapublic class Test { public static void main(String[] args) { String str1 = “Hello”; String str2 = “Hello”; String str3 = null; if (str1 != null) { System.out.println(str1.equals(str2)); } System.out.println(str1.equals(str3)); } } Output: true false 2. Using the == operator to compare Strings in Java public class Test { public static void main(String[] args) {…
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