How to remove the repetition of preferred countries. I need to add all the African countries as preferred countries in the dropdown list.
code i used for that.
preferredCountries: [ "gh", "dz","ao","bj","bw","bf","bi","cm","cf","td","km","cd","dj","eg","gq","er","sz","et","ga","gm","gq","gw","ke","ls","lr","ly","mg","mw","ml","mr","mu","ma","mz","na","ne","ng","rw","sn","sc","sl","so","za","ss","sd","tz","tg","tn","ug","zm","zw" ],
CodePudding user response:
You can use a Set to get the unique values here, then use the ... spread operator to return to an array:
preferredCountries = [ "gh", "dz","ao","bj","bw","bf","bi","cm","cf","td","km","cd","dj","eg","gq","er","sz","et","ga","gm","gq","gw","ke","ls","lr","ly","mg","mw","ml","mr","mu","ma","mz","na","ne","ng","rw","sn","sc","sl","so","za","ss","sd","tz","tg","tn","ug","zm","zw" ];
const uniqueCountries = [...new Set(preferredCountries)];
console.log({ uniqueCountries });
.as-console-wrapper { max-height: 100% !important; top: 0; }
Another example:
const values = [ 'a', 'a', 'a', 'b', 'b', 'b', 'c' ];
// Use spread operator and new Set()
let uniqueValues = [...new Set(values)];
console.log({ uniqueValues });
// Or use Array.from() and new Set()
uniqueValues = Array.from(new Set(values));
console.log({ uniqueValues });
.as-console-wrapper { max-height: 100% !important; top: 0; }
CodePudding user response:
You can avoid duplication of array by different ways
let preferredCountries: [ "gh", "dz","ao","bj","bw","bf","bi","cm","cf","td","km","cd","dj","eg","gq","er","sz","et","ga","gm","gq","gw","ke","ls","lr","ly","mg","mw","ml","mr","mu","ma","mz","na","ne","ng","rw","sn","sc","sl","so","za","ss","sd","tz","tg","tn","ug","zm","zw" ],
let NewpreferredCountries= [...new Set(chars)];
console.log(NewpreferredCountries);
Another Method is
let preferredCountries: [ "gh", "dz","ao","bj","bw","bf","bi","cm","cf","td","km","cd","dj","eg","gq","er","sz","et","ga","gm","gq","gw","ke","ls","lr","ly","mg","mw","ml","mr","mu","ma","mz","na","ne","ng","rw","sn","sc","sl","so","za","ss","sd","tz","tg","tn","ug","zm","zw" ],
let NewpreferredCountries= preferredCountries.filter((c, index) => {
return preferredCountries.indexOf(c) === index;
});
console.log(NewpreferredCountries);
You can also remove duplicates from an array using forEach() and include()
let preferredCountries: [ "gh", "dz","ao","bj","bw","bf","bi","cm","cf","td","km","cd","dj","eg","gq","er","sz","et","ga","gm","gq","gw","ke","ls","lr","ly","mg","mw","ml","mr","mu","ma","mz","na","ne","ng","rw","sn","sc","sl","so","za","ss","sd","tz","tg","tn","ug","zm","zw" ],
let NewpreferredCountries= [];
preferredCountries.forEach((c) => {
if (!NewpreferredCountries.includes(c)) {
NewpreferredCountries.push(c);
}
});
console.log(NewpreferredCountries);