1、空参构造 new StringBuffer();
默认分配的初始化缓冲区的大小是16
源码:
public StringBuffer() {
super(16);
}
2、new StringBuffer(int capacity);
默认初始化缓冲区大小是其传入的值的大小
源码:
public StringBuffer(int capacity) {
super(capacity);
}
3.new StringBuffer(String str);
默认初始化缓冲区大小是16+str.length
源码:
public StringBuffer(String str) {
super(str.length() + 16);
append(str);
}
4.new StringBuffer(CharSequence seq);
默认初始化缓冲区大小和3一样,都是
源码:
public StringBuffer(CharSequence seq) {
this(seq.length() + 16);
append(seq);
}