一个对象只有一个hashcode,多个对象的hashcode可能相同。
源代码位置:java-source/java/lang/String.java,hashCode()方法:
public int hashCode() { int h = hash; if (h == 0 && value.length > 0) { char val[] = value; for (int i = 0; i < value.length; i++) { h = 31 * h + val[i]; } hash = h; } return h; }
关于这个实现:
Why does Java‘s hashCode() in String use 31 as a multiplier?
Consistency of hashCode() on a Java string
时间: 2024-08-05 11:13:26