string methods in java  

You can pass strings around your code and call string methods directly, or you can create a String variable to store that string.

The second approach is safer and clearer, but the first one is more concise. Which one to use? Let’s find out. We know Java strings are immutable, which means we cannot change their value after they are created.

We cannot concatenate two strings with the plus sign operator; instead, we must use the append method of the StringBuilder class to build a new string from substrings.

If you come from a C background, you may be more comfortable using direct access to string methods as global functions rather than creating local variables and assigning them in your code.

In this article you will learn about different options for working with Java strings when it comes to scope and readability.

Using String Interpolation – string methods in java

String interpolation is a way of creating a new string from other strings, variables, and expressions from inside the same string, without concatenation.

Whenever you see a dollar sign with a number inside parentheses after a string, that string is using string interpolation.

If you are using a modern IDE (Integrated Development Environment) like IntelliJ or Eclipse, you can see the string interpolation syntax in the code editor.

Let’s look at an example of interpolation. There are two strings, first and last. We want to display “Hello, My Name is ” + first + ” ” + last + “!” There are three ways to do this: String interpolation uses the same syntax inside the string.

We write the first and last strings and then follow each one with a dollar sign and the variables’ names: $first $last. In the IDE, you’ll see the variables represented by a dollar sign.

Using the plus sign operator to create a string – string methods in java

The plus sign operator is used for concatenation when building a string. We use it in the same way we use it with numbers: to add two strings together. We do this by concatenating the two strings together with a plus sign.

An example of this is the following code:

In this example, we have two strings, “Hello ” and “My Name is ” and we are building a new string by adding the two strings together. The plus sign concatenates the strings together to create one string.

When you are concatenating strings, you need to make sure to use the correct string type. If the first string is a byte string, you must use the byte notation. If the first string is a double-string, you must use the double notation.

Using Object Creation – string methods in java

Object creation is used to create a string from a literal value, such as “Hello World”. With this method, you are not building a string but rather creating a new string from a literal value and storing it as a String object.

The following code is an example of this:

In this example, we are creating a new String object from the literal value “Hello World”. We are not concatenating the literal string with another string. We are creating a new object.

The following example uses the same code, but we are building a new String object from a concatenation of two strings:

Concatenation with the plus sign operator and creating a new String

In this example, we are creating a new String object with the concatenation of two strings, but we are not using the plus sign operator. Instead of using the plus sign operator, we create a new String object to replace the plus sign operator.

The following example uses the same code, but we are building a new String object from a concatenation of two strings without using the plus sign operator:

Instance Methods for Strings – string methods in java

There are many instance methods for the String class. These functions can be used on a string directly by calling the method on the string. For example, you can use the length() method on a string to return the length of that string.

The following code example shows the usage of the length() method on a string:

In this example, we are calling the length() method on the “Java” string to return the length of that string. The output from this code is 10, which is the length of “Java”.

The replace() method can be used to replace all occurrences of a substring with a new string. The replaceAll() method can be used to replace all occurrences of a substring with multiple strings.

The following example shows the usage of the replace() and replaceAll() methods on a string:

In this example, we are using the replace() and replaceAll() methods on the “Java” string to return a new string. The replace() method replaces all the occurrences of the “o” with an “a”. The replaceAll() method replaces all occurrences of the “o” with both an “a” and an “e”. The output from this example is “Jav a”.

Static Methods for Strings – string methods in java

There are many static methods for the String class. These functions can be used on a string directly by calling the method on the string.

The following code example shows the usage of the isEmpty() method on the “Java” string to return a boolean value:

In this example, we are calling the isEmpty() method on the “Java” string to return a boolean value. The output from this code is false, which means the “Java” string is not empty.

The code example below shows the usage of the isBlank() method on the “Java” string to return a boolean value:

In this example, we are calling the isBlank() method on the “Java” string to return a boolean value. The output from this code is true, which means the “Java” string is blank.

The code example below shows the usage of the isEmpty() method on the “Java” string to return a boolean value:

In this example, we are calling the isEmpty() method on the “Java” string to return a boolean value. The output from this code is false, which means the “Java” string is not empty.

Conclusion – string methods in java

What you use to work with strings in Java will depend on your situation. If you are creating a one-off script, you may prefer methods that are more concise and verbose.

If you are writing code that will be used by other developers, however, it is probably better to use a more verbose approach with variables.

If you are writing code that will be used by other developers, it is probably better to use a more verbose approach with variables. If you are creating a one-off script, however, you may be better off using methods that are more concise and verbose.