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								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								id: 5675e877dbd60be8ad28edc6
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								title: Iterate Through an Array with a For Loop
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								challengeType: 1
							 
						 
					
						
							
								
									
										
										
										
											2019-02-14 12:24:02 -05:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								videoUrl: 'https://scrimba.com/c/caeR3HB'
							 
						 
					
						
							
								
									
										
										
										
											2019-07-31 11:32:23 -07:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								forumTopicId: 18216
							 
						 
					
						
							
								
									
										
										
										
											2021-01-13 03:31:00 +01:00 
										
									 
								 
							 
							
								
									
										 
								
							 
							
								 
							
							
								dashedName: iterate-through-an-array-with-a-for-loop
							 
						 
					
						
							
								
									
										
										
										
											2018-09-30 23:01:58 +01:00 
										
									 
								 
							 
							
								
							 
							
								 
							
							
								---
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --description--
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								A common task in JavaScript is to iterate through the contents of an array. One way to do that is with a `for`  loop. This code will output each element of the array `arr`  to the console:
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
									
										
										
										
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								var arr = [10, 9, 8, 7, 6];
							 
						 
					
						
							
								
									
										
										
										
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								for (var i = 0; i <  arr.length ;  i + + )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								   console.log(arr[i]);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								Remember that arrays have zero-based indexing, which means the last index of the array is `length - 1` . Our condition for this loop is `i < arr.length` , which stops the loop when `i`  is equal to `length` . In this case the last iteration is `i === 4`  i.e. when `i`  becomes equal to `arr.length`  and outputs `6`  to the console.
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								# --instructions--
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								Declare and initialize a variable `total`  to `0` . Use a `for`  loop to add the value of each element of the `myArr`  array to `total` .
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								# --hints--
  
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								`total`  should be declared and initialized to 0. 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								assert(code.match(/(var|let|const)\s*?total\s*=\s*0.*?;?/));
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								`total`  should equal 20. 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								assert(total === 20);
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
									
										
										
										
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								You should use a `for`  loop to iterate through `myArr` .
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
									
										
										
										
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								assert(/for\s*\(/g.test(code) &&  /myArr\s*\[/g.test(code));
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
									
										
										
										
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								You should not attempt to directly assign the value 20 to `total` .
							 
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								assert(!__helpers.removeWhiteSpace(code).match(/total[=+-]0*[1-9]+/gm));
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								# --seed--
  
						 
					
						
							
								
									
										
										
										
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								## --after-user-code--
  
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
									
										
										
										
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								(function(){if(typeof total !== 'undefined') { return "total = " + total; } else { return "total is undefined";}})()
							 
						 
					
						
							
								
									
										
										
										
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								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
									
										
										
										
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								## --seed-contents--
  
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								// Setup
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								var myArr = [ 2, 3, 4, 5, 6];
							 
						 
					
						
							
								
									
										
										
										
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								// Only change code below this line
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								# --solutions--
  
						 
					
						
							
								
									
										
										
										
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								```js
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								var myArr = [ 2, 3, 4, 5, 6];
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								var total = 0;
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								for (var i = 0; i <  myArr.length ;  i + + )  { 
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								  total += myArr[i];
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								}
							 
						 
					
						
							
								
							 
							
								
							 
							
								 
							
							
								```