Solved lab

src/presidents.js

@@ -419,47 +419,74 @@ const presidents = [
 
 
 // Iteration 1 | Names of All Presidents - `map()`
-function getNames(presidentsArr) {}
+function getNames(presidentsArr) {
+  return presidentsArr.map((president) => president.name);
+}
 
 
 
 
 // Iteration 2 | Democratic Presidents - `filter()`
-function getDemocraticPresidents(presidentsArr) {}
+function getDemocraticPresidents(presidentsArr) {
+  return presidentsArr.filter((president) => president.party === "Democratic");
+}
 
 
 
 
 // Iteration 3 | Count Years in Office - reduce()
-function  countYearsInOffice(presidentsArr) {}
+/*Important: You should skip the president who is still in office (the president with the leftOffice property set to null) and not include them in the total years.*/
+function  countYearsInOffice(presidentsArr) {
+  return presidentsArr.reduce((totalYears, president) => {
+    if (president.leftOffice) {
+      totalYears += president.leftOffice - president.tookOffice;
+    }
+    return totalYears;
+  }, 0);
+}
 
 
 
 
 // Iteration 4 | Sort Presidents by Birth Year - `sort()`
-function sortPresidentsByBirthYear(presidentsArr) {}
+function sortPresidentsByBirthYear(presidentsArr) {
+  return presidentsArr.sort((a, b) => a.birthYear - b.birthYear);
+}
 
 
 
 
 // Bonus: Iteration 5 | Age at Inauguration - `map()`
-function getAgeAtInauguration(presidentsArr) {}
+function getAgeAtInauguration(presidentsArr) {
+  return presidentsArr.map((president) => {
+    return {
+      name: president.name,
+      ageAtInauguration: president.tookOffice - president.birthYear
+    };
+  });
+}
 
 
 
 
 // Bonus: Iteration 6 | Presidents Born After - `filter()`
-function getPresidentsBornAfter(presidentsArr, year) {}
+function getPresidentsBornAfter(presidentsArr, year) {
+  return presidentsArr.filter((president) => president.birthYear > year);
+}
 
 
 
 
 // Bonus: Iteration 7 | Count Republican Presidents
-function countRepublicanPresidents(presidentsArr) {}
+function countRepublicanPresidents(presidentsArr) {
+  return presidentsArr.filter((president) => president.party === "Republican").length;
+}
 
 
 
 
 // Bonus: Iteration 8 | Sort Presidents by Name - `sort()`
-function sortPresidentsByName(presidentsArr) {}
+function sortPresidentsByName(presidentsArr) {
+  return presidentsArr.sort((a, b) => a.name.localeCompare(b.name));
+}