Nodejs Array Convert to_frequency()

Method Source Code

// Returns a hash (number:frequency) having the numbers as keys and their frequency as values
Array.prototype.to_frequency = function(){
  hashed_picks = {}/*w  w w. j av  a2s  . com*/
  for (var i = 0; i < this.length; i++){
    pick = this[i].toString()
    if (hashed_picks[pick] == undefined){
      hashed_picks[pick] = 1
    }else{
      hashed_picks[pick]++
    }
  }
  
  return hashed_picks
}

Related

1. toSource(seen)

   Array.prototype.toSource = function(seen){
     var source, i = 0, j = this.length;
     seen = seen || [this];
     source = '[';
     for(;i<j;i++){
       source+= Object.sourceOf(this[i], seen, '[]');
       if( i < j - 1 ) source+= ', ';
     source+= ']';
   ...
   

2. toStrGen(originStr)

   Array.prototype.toStrGen=function(originStr){
     if(Object.prototype.toString.call(originStr).slice(8,-1)==="Array"){
       return this.map(function(i){
         return originStr.join(i);
       }).reduce(function(m,n){return m+n+'\b'}, "");
   };
   

3. toUnique()

   Array.prototype.toUnique = function() {
       var dict = {},
           arrayLength = this.length,
           elem,
           i,
           key,
           uniqueArray = [];
       for (i = 0; i < arrayLength; i++) {
           elem = this[i];
   ...
   

4. toUniqueDictionary(key)

   Array.prototype.toUniqueDictionary = function(key) {
     if (!key)
       key = function(x) { return x.id; };
     var dictionary = {};
     this.forEach(function(item) {
       var currentKey = key(item);
       if (!currentKey)
         return true;
       dictionary[currentKey] = item;
   ...
   

5. toUpper()

   Array.prototype.toUpper = function() {
     return this.map(function(x) { return x.toUpperCase(); });
   

6. to_s()

   Array.prototype.to_s = function(){return this.join('');};