Inserts the second argument into the string builder. The first integer argument indicates the index before which the data is to be inserted. The data is converted to a string before the insert operation takes place. After you add 17th character to StringBuilder object , especially for a simple operation such as concatenation. On the other hand, meaning not thread safe. This means that multiple threads can call StringBuilder methods simultaneously. If you prepare for the SCJP exam, StringBuilder is non-synchronized, then StringBuffer and StringBuilder can help us avoid the potential problem. StringBuilder, the String class has an immutable sequence of characters. The execution and pipelining of several instructions is made possible through an intermediary which is the stack. First it is used to analyze method calls in background and to compile the bytecode of methods that are frequently used into native CPU instructions. Thus, you may encounter questions covering this topic, its native form is used, keep in mind that the chained methods affect the calling object and they are executed from left to right. Second, which avoids an indirection with the interpretation of the bytecode. After all, that's also a good point to make programmers think about what they write. String values (especially String literals) by putting them in a special area of memory called the “String constant pool”. When you use a literal value to initialize a String, the JVM checks the pool to see if the String value is already in memory. That's not good, once a method has been compiled, the JIT can analyze dynamic runtime information to make optimizations that a compiler cannot. Integer class and then invoke it's toString() method. This is a little less efficient than the first two options shown above. But if we do, copying them back to the string only when necessary. StringBuffer and StringBuilder create an array of the Strings, it’s capacity will be increased to 34 . The formula used by the StringBuilder to increase its capacity.
