今天做了String和Stringbuffer累加不同次数耗时对比
static void testStrAdd(){ String s = ""; long start = System.currentTimeMillis(); for (int i = 0; i < 10000; i++) { s+=i+"\n"; } long end = System.currentTimeMillis(); System.out.println(end-start); }StringBuffer 增加测试
static void testStringBuffAdd(){ StringBuffer sb = new StringBuffer(); long start = System.currentTimeMillis(); for (int i = 0; i < 10000000; i++) { sb.append(i).append("\n"); } long end = System.currentTimeMillis(); System.out.println(end-start); }
1w次 | 10w次 | 100w次 | |
String | 375 | 47818 | 无法测试了 |
StringBuffer | 13 | 40 | 136 |
从测试结果可以看出 ,Stringbuffer累加结果性能:
String累加1w次,StringBuffer可以累加300w次左右