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SbDemo.java
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37 lines (32 loc) · 1.09 KB
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/**
* @program JavaBooks
* @description: String StringBuffer StringBuilder
* @author: mf
* @create: 2020/02/07 19:13
*/
package com.strings;
public class SbDemo {
public static void main(String[] args) {
// String
String str = "hello";
long start = System.currentTimeMillis();
for (int i = 0; i < 100000; i++) {
str += i; // 创建多少个对象，，
}
System.out.println("String: " + (System.currentTimeMillis() - start));
// StringBuffer
StringBuffer sb = new StringBuffer("hello");
long start1 = System.currentTimeMillis();
for (int i = 0; i < 1000000; i++) {
sb.append(i);
}
System.out.println("StringBuffer: " + (System.currentTimeMillis() - start1));
// StringBuilder
StringBuilder stringBuilder = new StringBuilder("hello");
long start2 = System.currentTimeMillis();
for (int i = 0; i < 1000000; i++) {
stringBuilder.append(i);
}
System.out.println("StringBuilder: " + (System.currentTimeMillis() - start2));
}
}