Algorithm Diff Two Arrays - thelastmile/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.
try to solve the problem now
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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