StringBuilder insert () vs append () performance?

Question

Is there any performance difference in the insert () vs append () from the StringBuilder class? I will create many short strings as text identifiers and ask myself this question ... Should I initialize SB with a separator and use insert + append or just add?

Answer 1

Knowing that:

• An insertat the end of the string representation is equivalent appendin terms of time complexity (O (n)).
• And insertsomewhere else, and not at the end, it cannot receive append(since they have different goals).
• , insert 3 System.arraycopy () , append 1.

:

• , append
• insert

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Answer 2

,

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, append, .

Answer 3

According to Java API docs. You must provide an offset if using an insert.

StringBuilder.insert(5, "String");

but StringBuilder.append("string")no. I guess append has better performance than insert.