2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								id: 56bbb991ad1ed5201cd392cc
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								title: Manipulate Arrays With pop()
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								challengeType: 1
							 
						 
					
						
							
								
									
										
										
										
											2019-02-14 12:24:02 -05:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								videoUrl: 'https://scrimba.com/c/cRbVZAB'
							 
						 
					
						
							
								
									
										
										
										
											2019-07-31 11:32:23 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								forumTopicId: 18236
							 
						 
					
						
							
								
									
										
										
										
											2021-01-13 03:31:00 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								dashedName: manipulate-arrays-with-pop
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# --description--
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Another way to change the data in an array is with the `.pop()`  function.
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-03-02 16:12:12 -08:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								`.pop()`  is used to pop a value off of the end of an array. We can store this popped off value by assigning it to a variable. In other words, `.pop()`  removes the last element from an array and returns that element. 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-03-02 16:12:12 -08:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								Any type of entry can be popped off of an array - numbers, strings, even nested arrays.
							 
						 
					
						
							
								
									
										
										
										
											2019-05-17 06:20:30 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								var threeArr = [1, 4, 6];
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								var oneDown = threeArr.pop();
							 
						 
					
						
							
								
									
										
										
										
											2021-03-02 16:12:12 -08:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								console.log(oneDown);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								console.log(threeArr);
							 
						 
					
						
							
								
									
										
										
										
											2019-05-17 06:20:30 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-03-02 16:12:12 -08:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								The first `console.log`  will display the value `6` , and the second will display the value `[1, 4]` .
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# --instructions--
  
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2021-03-02 16:12:12 -08:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								Use the `.pop()`  function to remove the last item from `myArray` , assigning the popped off value to `removedFromMyArray` .
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# --hints--
  
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								`myArray`  should only contain `[["John", 23]]` . 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								assert(
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  (function (d) {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if (d[0][0] == 'John' & &  d[0][1] === 23 & &  d[1] == undefined) {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      return true;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } else {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      return false;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  })(myArray)
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								);
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								You should use `pop()`  on `myArray` .
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								assert(/removedFromMyArray\s*=\s*myArray\s*.\s*pop\s*(\s*)/.test(code));
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								`removedFromMyArray`  should only contain `["cat", 2]` . 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								assert(
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  (function (d) {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    if (d[0] == 'cat' & &  d[1] === 2 & &  d[2] == undefined) {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      return true;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    } else {
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								      return false;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								    }
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  })(removedFromMyArray)
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								);
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# --seed--
  
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								## --after-user-code--
  
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
									
										
										
										
											2018-10-20 21:02:47 +03:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								(function(y, z){return 'myArray = ' + JSON.stringify(y) + ' &  removedFromMyArray = ' + JSON.stringify(z);})(myArray, removedFromMyArray);
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								## --seed-contents--
  
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// Setup
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								var myArray = [["John", 23], ["cat", 2]];
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								// Only change code below this line
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								var removedFromMyArray;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
											2020-11-27 19:02:05 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								# --solutions--
  
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								var myArray = [["John", 23], ["cat", 2]];
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								var removedFromMyArray = myArray.pop();
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```