Nodejs Array Filter filter(predicateFunction)

Method Source Code

/** //from www . j a  v a2  s  .co m
 * Filter is built into JavaScript, but here is how it looks.
 */
/*
Array.prototype.filter = function(predicateFunction) {
   var results = [];
   this.forEach(function(itemInArray) {
      if (predicateFunction(itemInArray)) {
         results.push(itemInArray);
      }
   });

   return results;
};*/  

var result = ['A','B','C','D','E','F'].filter(function(x) { 
   return x > 'C'
});

console.log(result);
var outcome = JSON.stringify(result);
console.log(outcome);
var testOutCome = outcome === '["D","E","F"]';
console.log(testOutCome);

Related

1. filter(predicate)

   Array.prototype.filter = function (predicate) {
       let result = [];
       this.forEach(item => {
           if (predicate(item)) {
               result.push(item);
       })
       return result;
   };
   ...
   

2. filter(predicate)

   Array.prototype.filter = function(predicate) {
     var filtered_array = [];
     this.forEach(function (element, i) {
       if (predicate(element)) filtered_array.push(element);
     });
     return filtered_array;
   

3. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction) {
     var results = [];
     this.forEach(function(itemInArray) {
       if (predicateFunction(itemInArray)) {
       results.push(itemInArray);
     });
     return results;
   };
   ...
   

4. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction) {
     var results = [];
     this.forEach(function(itemInArray) {
       if(predicateFunction(itemInArray) == true)
         results.push(itemInArray);
     });
     return results;
   };
   

5. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction){
     var result = [];
     this.forEach(function(item){
       if(predicateFunction(item)) {
         result.push(item);
     })
     return result;
   Array.prototype.map = function(predicateFunction){
     var result = [];
     this.forEach(function(item){
       result.push(predicateFunction(item));
     })
     return result;
   var a = [1,2,3,4,5,6,7,8,9];
   a.map(function(x){
     return x*2;
   }).filter(function(x){
     if(x > 4) return true;
   })
   

6. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction) {
     var results = [];
     this.forEach(function(itemInArray) {
       if (predicateFunction(itemInArray)) {
       results.push(itemInArray);
     });
     return results;
   };
   ...
   

7. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction) {
     var results = [];
     this.forEach(itemInArray => {
       if(predicateFunction(itemInArray)) {
          results.push(itemInArray);
     });
     return results;
   };
   ...
   

8. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction) {
     var results = [];
     this.forEach(function(itemInArray) {
       if (predicateFunction(itemInArray)) {
       results.push(itemInArray);
     });
     return results;
   };
   ...
   

9. filter(predicateFunction)

   Array.prototype.filter = function(predicateFunction) {
     var results = [];
     this.forEach(function(item) {
       if (predicateFunction(item)) {
         results.push(item);
     });
     return results;