Nodejs Array Where where(inclusionTest)

Method Source Code

Array.prototype.where = function (inclusionTest) {
    var results = [];
    for (var i = 0; i < this.length; i++) {
        if (inclusionTest(this[i]))
            results.push(this[i]);/*from  w w  w.j  a  v  a  2  s  . c om*/
    }
    return results;
};

Array.prototype.select = function (projection) {
    var results = [];
    for (var i = 0; i < this.length; i++) {
        results.push(projection(this[i]));
    }
    return results;
};
const children = [{ id: 1, Name: "Rob" }, { id: 2, Name: "Sansa" }, { id: 3, Name: "Arya" }, { id: 4, Name: "Brandon" }, { id: 5, Name: "Rickon" }];
var filteredChildren = children.where(function (x) { return x.id % 2 == 0; }).select(function (x) { return x.Name; });
console.dir(children);
console.dir(filteredChildren);

Related

1. where(f)

   Array.prototype.where = function(f){
      var fn = f;
      if(typeof f == 'string'){
         if((fn=lambda(fn)) == null){
            throw "Syntax error in lambda string: "+ f;
   };
   

2. where(f)

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

3. where(func)

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

4. where(func)

   Array.prototype.where = function(func){
     var result = [];
     forEach(this, function (element) {
       if(func(element)){
         result.push(element);
     });
     return result;
   

5. where(func)

   Array.prototype.where = function (func) {
       var items = [],
           length = this.length;
       for (var i = 0; i < length; i++) {
           if (func(this[i]))
               items.push(this[i]);
       return items.length === 0 ? null : items;
   

6. where(inclusionTest)

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

7. where(predicate)

   Array.prototype.where = function(predicate) {
       var derivedArray = [];
       for (i = 0; i < this.length; i += 1) {
           if (predicate(this[i])) {
               derivedArray.push(this[i]);
       return derivedArray;
   

8. where(predicate)

   Array.prototype.where = function (predicate) {
       if (predicate == null || typeof (predicate) !== 'function') throw new Error('predicate should');
       var result = [];
       for (var i = 0; i < this.length; i++) {
           if (predicate(this[i], i)) result.push(this[i]);
       return result;
   };
   

9. where(predicate)

   Array.prototype.where = function (predicate) {
       var ret = [];
       for (var i = 0; i < this.length; ++i) {
           if (predicate(this[i], i))
               ret.push(this[i]);
       return ret;
   };