Stringbuilder清空效率
2018-02-09，本文 838 字，阅读全文约需 3 分钟
StringBuilder builder = new StringBuilder(); long time = System.currentTimeMillis();
for(int i=0;i<10000000;i++){
builder = new StringBuilder();
builder.append("aa");
builder.append("bb");
builder.append("cc");
builder.append("dd");
builder.append("ee");
}
System.out.println("new 耗时：" + (System.currentTimeMillis() - time));
long time1 = System.currentTimeMillis();
for(int i=0;i<10000000;i++){
builder.delete(0, builder.length());
builder.append("a");
builder.append("b");
builder.append("c");
builder.append("d");
builder.append("e");
}
System.out.println("delete 耗时：" + (System.currentTimeMillis() - time1));
long time2 = System.currentTimeMillis();
for(int i=0;i<10000000;i++){
builder.setLength(0);
builder.append("1a");
builder.append("1b");
builder.append("1c");
builder.append("1d");
builder.append("1e");
}
System.out.println("setLenth=0 耗时：" + (System.currentTimeMillis() - time2));