Algorithm Diff Two Arrays - ashish9342/FreeCodeCamp GitHub Wiki
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Check two arrays and return a new array that contains only the items that are not in either of the original arrays.
- for Loop (Devdocs)
- Array.prototype.includes (Devdocs)
- Array.prototype.filter (Devdocs)
- Array.prototype.concat (Devdocs)
Merge the list to make it easy to compare functions.
try to solve the problem now
Use filter to get the new array, you will need to create a callback function.
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The best way to go about the callback function is to check if the number from the new merged array is not in both original arrays and return it.
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Solution ahead!
function diffArray(arr1, arr2) {
var newArr = [];
// Looping through arr1 to find elements that do not exist in arr2
for (var i = 0; i < arr1.length; i++) {
if (arr2.indexOf(arr1[i]) === -1){
// Pushing the unique to arr1 elements to the newArr
newArr.push(arr1[i]);
}
}
// Looping through arr2 to find elements that do not exist in arr1
for (var j = 0; j < arr2.length; j++) {
if (arr1.indexOf(arr2[j]) === -1){
// Pushing the unique to arr2 elements to the newArr
newArr.push(arr2[j]);
}
}
return newArr;
}
diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]);
Read the comments in the code.
function diffArray(arr1, arr2) {
return arr1
.concat(arr2)
.filter(
item => !arr1.includes(item) || !arr2.includes(item)
)
}
diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]);
Explain solution here and add any relevant links
- Array.prototype.concat (Devdocs)
- Array.prototype.filter (Devdocs)
- Array.prototype.includes (Devdocs)
function diffArray(arr1, arr2) {
return arr1
.filter(el => !arr2.includes(el))
.concat(
arr2.filter(el => !arr1.includes(el))
)
}
diffArray([1, 2, 3, 5], [1, 2, 3, 4, 5]);
Explain solution here and add any relevant links
- Array.prototype.includes (Devdocs)
- Array.prototype.filter (Devdocs)
- Array.prototype.concat (Devdocs)
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Thanks @Rafase282 @aganita @abhisekp for your help with Challenge: Diff Two Arrays
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