javascript中实现兼容JAVA的hashCode算法代码分享

public int hashCode() {
int h = hash;
if (h == 0) {
int off = offset;
char val[] = value;
int len = count;

for (int i = 0; i < len; i++) {
h = 31*h + val[off++];
}
hash = h;
}
return h;
}

<script type="text/javascript">
function hashCode(str){
     var h = 0, off = 0;
     var len = str.length;
     for(var i = 0; i < len; i++){
       h = 31 * h + str.charCodeAt(off++);
     }
     return h;
   }
   alert(hashCode('沈阳'));
  </script>

<script>
function hashCode(str){
     var h = 0, off = 0;
     var len = str.length;
     for(var i = 0; i < len; i++){
       h = 31 * h + str.charCodeAt(off++);
     }
   var t=-2147483648*2;
   while(h>2147483647){
    h+=t
   }
     return h;
   }
alert(hashCode('沈阳沈阳啊'));

</script>

<script>
  function hashCode(str) {
    var h = 0;
    var len = str.length;
    var t = 2147483648;
    for (var i = 0; i < len; i++) {
      h = 31 * h + str.charCodeAt(i);
      if(h > 2147483647) h %= t;//java int溢出则取模
    }
    /*var t = -2147483648 * 2;
    while (h > 2147483647) {
      h += t
    }*/
    return h;
  }
  alert(hashCode('C#同一时间N个线程在并发执行,其余在队列中如何实现')); //1107373715
</script>

String.prototype.hashCode = function(){
	var hash = 0;
	if (this.length == 0) return hash;
	for (i = 0; i < this.length; i++) {
		char = this.charCodeAt(i);
		hash = ((hash<<5)-hash)+char;
		hash = hash & hash; // Convert to 32bit integer
	}
	return hash;
}

String.prototype.hashCode = function() {for (var a = 31,b = 0,c = this.length; b < c;) a ^= (a << 5) + (a >> 2) + this.charCodeAt(b++); return a};