Nodejs Array Compact compact()

Method Source Code

Array.prototype.compact = function() {
  return this.filter(function(i) {if (i) return true})
}

Array.prototype.collect = function(key) {
  return this.map(function(i){return i[key]})
}

Array.prototype.avg = function(key) {
  return eval(this.join('+')) / this.length;
}

Array.prototype.stats = function() {
  var avg = this.avg();
  var diff2 = this.map(function(i) {return (i-avg)*(i-avg)});
  var diff2avg = diff2.avg();
  return {//  w  w  w .jav  a  2s  . c o  m
    diff2: diff2,
    var: diff2avg,
    std: Math.sqrt(diff2avg),
    avg: avg,
    total: this.length
  }
}

//Takes [{a: 'a1', b: 'b1'},{a: 'a2', b: 'b2'},{a: 'a2', b: 'yes'}].reduceToHash('a','b') ==> {a1: ['b1'], a2: ['b2','yes']}
Array.prototype.reduceToHash = function(key, val) {
  var tmp = {};
  this.forEach(function (i) {
    var k = i[key];
    var v = i[val];
    if (!tmp.hasOwnProperty(k))
      tmp[k] = [];
    tmp[k].push(v)
  });
  return tmp;
}

Related

1. compact()

   Array.prototype.compact = function () { 
     return this.filter((a) => a) 
   

2. compact()

   Array.prototype.compact = function()
       var a = [];
       for( var i = 0; i < this.length; i++ ) {
           if( i in this ) 
               if( this[ i ] != "" ) a.push( this[ i ] );
       return a;
   };
   ...
   

3. compact()

   Array.prototype.compact = function(){
       var ca = [];
       for(var i in this){
           if (this.hasOwnProperty(i)) {
               if ( present(this[i]) ) {
                   ca.push(this[i]);
       return ca;
   };
   

4. compact()

   Array.prototype.compact = function(){
       var compacted = [];
       for(var i = 0; i < this.length ; i++){
           if(this[i]){
               compacted.push(this[i]);
       };
       return compacted;
   };
   ...
   

5. compact()

   Array.prototype.compact = function () {
     return this.filter((value) => {
       return value;
     });
   };
   

6. compact()

   Array.prototype.compact = function() {
     return this.reduce(function(res, el) {
       if(el !== null) {
         res.push(el);
       };
       return res;
     }, [])
   

7. compact()

   Array.prototype.compact = function() {
       return this.filter(function (i) {
           return !!i;
       });
   };
   

8. compact()

   Array.prototype.compact = function() {
       var comp = [];
       for (var i = 0;i < this.length; i++) {
           if (this[i]) {
               comp.push(this[i]);
       return comp;
   

9. compact(deleteValue)

   Array.prototype.compact = function(deleteValue) {
     for (var i = 0; i < this.length; i++) {
       if (this[i] == deleteValue) {
         this.splice(i, 1);
         i--;
     return this;
   };
   ...