Nodejs String Hash hashCode()

Method Source Code

String.prototype.hashCode = function() {
  var hash = 0, i, chr, len;
  if (this.length == 0) return hash;
  for (i = 0, len = this.length; i < len; i++) {
    chr   = this.charCodeAt(i);/*from   w  w  w  .j  a  v  a2 s .  co m*/
    hash  = ((hash << 5) - hash) + chr;
    hash |= 0; // Convert to 32bit integer
  }
  return hash;
};

String.prototype.myHashCode = function() {
   var hash;
   var numString = "";
   var stringCopy = this + "*****";
   for (var i = 0; i < 2; i++) {
      var lastIndex = stringCopy.charCodeAt(i).toString().length - 1;
      numString += stringCopy.charCodeAt(i).toString()[lastIndex];
   }
   var hash = parseInt(numString);
   return hash;
}

var makeRandomStrings = function(numStrings) {
   var stringArray = [];
   for (var i = 0; i < numStrings; i++){
      stringArray.push(Math.random().toString(36).substring(7));
   }
   return stringArray;
}

var realHashConvert = function(string) {
   return string.hashCode() % 50 + 50;;
}

var myHashConvert = function(string) {
   return string.myHashCode();
}

// Tests

var testStrings = makeRandomStrings(1000);

var realHashes = testStrings.map(realHashConvert);

var myHashes = testStrings.map(myHashConvert);

console.log (testStrings, realHashes, myHashes)

Related

1. hashCode()

   String.prototype.hashCode = function() {
       var hash = 0,
           i,
           chr,
           len;
       if (this.length == 0)
           return hash;
       for (i=0,len=this.length;i<len;i++){
           chr   = this.charCodeAt(i);
   ...
   

2. hashCode()

   String.prototype.hashCode = function(){
       var hash = 0, i, char;
       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; 
       return hash;
   ...
   

3. hashCode()

   String.prototype.hashCode = function() {
     var hash = 0, i, chr, len;
     if (this.length === 0) return hash;
     for (i = 0, len = this.length; i < len; i++) {
       chr   = this.charCodeAt(i);
       hash  = ((hash << 5) - hash) + chr;
       hash |= 0; 
     return hash;
   ...
   

4. hashCode()

   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; 
   ...
   

5. hashCode()

   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;
     return hash;
   ...
   

6. hashCode()

   String.prototype.hashCode = function(){
     var hash = 0;
     if (this.length === 0) return hash;
     for (i = 0; i < this.length; i++) {
       chr = (this.charCodeAt(i) * 2.2); 
       hash = ((hash<<32)-hash)+chr; 
       hash = hash & hash; 
     return hash;
   ...
   

7. hashCode()

   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; 
     return hash;
   ...
   

8. hashCode()

   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; 
   ...
   

9. hashCode()

   var Commons = function() {};
   String.prototype.hashCode = function() {
       var aux = "v1.0" + this;
       var hash = 0, i, chr, len;
       if (this.length === 0) return hash;
       for (i = 0, len = aux.length; i < len; i++) {
           chr   = aux.charCodeAt(i);
           hash  = ((hash << 5) - hash) + chr;
           hash |= 0; 
   ...