From a memory efficiency perspective, which approach is generally better?
// Version 1: Using string concatenation
function createHTML(items) {
let html = '<ul>';
for (let i = 0; i < items.length; i++) {
html += '<li>' + items[i] + '</li>';
}
html += '</ul>';
return html;
}
// Version 2: Using array join
function createHTML2(items) {
const parts = ['<ul>'];
for (let i = 0; i < items.length; i++) {
parts.push('<li>' + items[i] + '</li>');
}
parts.push('</ul>');
return parts.join('');
}
Version 2 using array join is generally more memory efficient: 1) String concatenation (+=) creates new string objects with each operation, potentially leading to many intermediate strings, 2) These intermediate strings need to be garbage collected, creating overhead, 3) Array.join() collects all pieces first and then performs a single concatenation operation, 4) This reduces the number of intermediate string allocations and subsequent garbage collection, 5) The difference becomes significant with larger lists or in performance-critical code, 6) Modern JavaScript engines have improved string concatenation performance, but array join is still typically more efficient for many concatenations, 7) For small numbers of items, the difference may be negligible, 8) This pattern demonstrates how data structure choices can impact memory efficiency even for seemingly simple operations.