Example 1: js delete duplicates from array
const names = ['John', 'Paul', 'George', 'Ringo', 'John'];
let unique = [...new Set(names)];
console.log(unique); // 'John', 'Paul', 'George', 'Ringo'
Example 2: javascript remove duplicate in arrays
// 1. filter()
function removeDuplicates(array) {
return array.filter((a, b) => array.indexOf(a) === b)
};
// 2. forEach()
function removeDuplicates(array) {
let x = {};
array.forEach(function(i) {
if(!x[i]) {
x[i] = true
}
})
return Object.keys(x)
};
// 3. Set
function removeDuplicates(array) {
array.splice(0, array.length, ...(new Set(array)))
};
// 4. map()
function removeDuplicates(array) {
let a = []
array.map(x =>
if(!a.includes(x) {
a.push(x)
})
return a
};
/THIS SITE/ "https://dev.to/mshin1995/back-to-basics-removing-duplicates-from-an-array-55he#comments"
Example 3: removing duplicates in array javascript
let arr = [1,2,3,1,1,1,4,5]
let filtered = arr.filter((item,index) => arr.indexOf(item) === index)
console.log(filtered) // [1,2,3,4,5]
Example 4: remove duplicates from array javascript
[...new Set(array)]
Example 5: javascript remove duplicates from array
function toUniqueArray(a){
var newArr = [];
for (var i = 0; i < a.length; i++) {
if (newArr.indexOf(a[i]) === -1) {
newArr.push(a[i]);
}
}
return newArr;
}
var colors = ["red","red","green","green","green"];
var colorsUnique=toUniqueArray(colors); // ["red","green"]
Example 6: js delete duplicates from array
const names = ['John', 'Paul', 'George', 'Ringo', 'John'];
function removeDups(names) {
let unique = {};
names.forEach(function(i) {
if(!unique[i]) {
unique[i] = true;
}
});
return Object.keys(unique);
}
removeDups(names); // // 'John', 'Paul', 'George', 'Ringo'