What is the difference between string and stringbuilder

That means, using the StringBuilder class can boost performance when concatenating many strings together in a loop. But immutable objects have some advantages also, such as they can be used across threads without fearing synchronization problems. On the other hand, when initializing a StringBuilder, you are going down in performance. Also many actions that you do with string can't be done with StringBuilder object.

Append "red" ; sb. Output: true false. Set ; import java. Output: java. StringBuilder cannot be cast to java. We can create a String object without using a new operator, which is not possible with a StringBuilder.

StringBuilder is speedy and consumes less memory than a string while performing concatenations. This is because string is immutable in Java, and concatenation of two string objects involves creating a new object. To illustrate, consider the following code, which logs the time taken by both string and StringBuilder objects on multiple concatenations.

Output will vary : The time taken by string concatenation: ns The time taken by StringBuilder concatenation: ns. Since String is immutable, its length is fixed. But StringBuilder has the setLength method, which can change the StringBuilder object to the specified length. A String can be used when immutability is required, or concatenation operation is not required. Append " the" ; Console. Append " east" ; Console.

String objects can be used across threads, whereas StringBuilder objects do not thread-safe. Thus, two or more threads can call StringBuilder methods simultaneously. As String objects are thread-safe, they provide synchronization, whereas StringBuilder does not provide synchronization. String class is used when the value of the string is going to remain constant throughout the program or when there are very fewer modifications required on it, whereas StringBuilder is used when many repeated modifications or heavy operations are required to perform on the string.

For a very less number of concatenations, the String class works faster as compared to StringBuilder because accommodating characters in buffer space and then converting the entire value to string again creates overhead. Thus, for the small number of concatenations, StringBuilder works slower as compared to the copy-by-value behaviour of the String class. To convert the String object to the StringBuilder object, we need to pass the String object to the StringBuilder class constructor, whereas the StringBuilder object can be converted to String using the ToString method.

ToString ;. String creates a new instance only when the value of the string changes. If you perform certain operations on a string that does not change its value, then String will not create any new instance creation. Two or more string literals with the same content may have the same memory location. This is a guide to the top difference between String vs StringBuilder. Here we also discuss the String vs StringBuilder key differences with infographics and comparison table. You may also have a look at the following articles to learn more —.