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75 lines
1.9 KiB
Markdown
75 lines
1.9 KiB
Markdown
---
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id: 5675e877dbd60be8ad28edc6
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title: Iterate Through an Array with a For Loop
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challengeType: 1
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forumTopicId: 18216
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dashedName: iterate-through-an-array-with-a-for-loop
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---
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# --description--
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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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const arr = [10, 9, 8, 7, 6];
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for (let i = 0; i < arr.length; i++) {
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console.log(arr[i]);
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}
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```
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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 - 1` and outputs `6` to the console. Then `i` increases to `5`, and the loop terminates because `i < arr.length` is `false`.
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# --instructions--
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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`.
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# --hints--
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`total` should be declared and initialized to 0.
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```js
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assert(__helpers.removeJSComments(code).match(/(var|let|const)\s*?total\s*=\s*0.*?;?/));
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```
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`total` should equal 20.
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```js
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assert(total === 20);
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```
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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(__helpers.removeJSComments(code)) && /myArr\s*\[/g.test(__helpers.removeJSComments(code)));
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```
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You should not attempt to directly assign the value 20 to `total`.
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```js
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assert(!__helpers.removeWhiteSpace(__helpers.removeJSComments(code)).match(/total[=+-]0*[1-9]+/gm));
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```
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# --seed--
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## --seed-contents--
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```js
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// Setup
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const myArr = [2, 3, 4, 5, 6];
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// Only change code below this line
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```
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# --solutions--
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```js
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const myArr = [2, 3, 4, 5, 6];
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let total = 0;
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for (let i = 0; i < myArr.length; i++) {
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total += myArr[i];
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}
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```
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