45 lines
1.1 KiB
Markdown
45 lines
1.1 KiB
Markdown
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---
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title: Use Caution When Reinitializing Variables Inside a Loop
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---
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## Use Caution When Reinitializing Variables Inside a Loop
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- This challenge must be solved by redefining the scope of `row[]`.
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- Below is an example of the desired matrix.
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```javascript
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[
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[0][0],
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[0][0],
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[0][0]
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]
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```
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- However the current matrix - seen below - is far from the desired matrix
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```javascript
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[
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[0][0][0][0][0][0],
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[0][0][0][0][0][0],
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[0][0][0][0][0][0]
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]
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```
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- This error occurs due to the `row[]` array being declared as a global variable outside of the nested for loop.
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- However, to fill the matrix correctly the `row[]` array must be reset after each iteration of the outer loop.
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## Solution
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```javascript
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function zeroArray(m, n) {
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let newArray = [];
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for (let i = 0; i < m; i++) {
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let row = []; /* <----- row has been declared inside the outer loop.
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Now a new row will be initialised during each iteration of the outer loop allowing
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for the desired matrix. */
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for (let j = 0; j < n; j++) {
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row.push(0);
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}
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newArray.push(row);
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}
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return newArray;
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}
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let matrix = zeroArray(3, 2);
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console.log(matrix);
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```
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