Arrays & Methods

1const languages = ["Python", "JavaScript", "Java", "C++"];
2 
3console.log(languages[0]);      // Python
4console.log(languages.length);  // 4
5console.log(languages.at(-1));  // C++ (last element)
6 
7// Modify
8languages.push("Go");           // Add to end
9languages.unshift("Rust");      // Add to start
10console.log(languages);

1const prices = [10, 20, 30, 40, 50];
2 
3// map — transform each element
4const doubled = prices.map(p => p * 2);
5console.log(doubled); // [20, 40, 60, 80, 100]
6 
7// filter — keep elements that pass a test
8const expensive = prices.filter(p => p > 25);
9console.log(expensive); // [30, 40, 50]
10 
11// reduce — accumulate into one value
12const total = prices.reduce((sum, p) => sum + p, 0);
13console.log(total); // 150