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Carmen Chow
Full Stack JavaScript Techdegree Student 578 PointsWhat is the reason for assigning an empty string to a variable?
Hello,
Can someone help me understand why and when you would initialize a variable to an empty string? I have come across this happening twice in the first JS unit. Here are the examples: Why is "let items = ''???"
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function createListItems(arr) {
let items = '';
for (let i = 0; i < arr.length; i++) {
items += <li>${arr[i]}</li>;
}
return items;
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function createListItems(arr) {
let items = '';
for (let i = 0; i < arr.length; i++) {
items += <li>${arr[i]}</li>;
}
return items;
1 Answer
martinjones1
Front End Web Development Techdegree Graduate 44,824 PointsIf you do not set the value of the variable, then it will have the value undefined;
Compare the two results below, this should help show the reason for setting the value to be an empty string;
Value set
const arr = [1, 2, 3];
let items = '';
for (let i = 0; i < arr.length; i++) {
items += `<li>${arr[i]}</li>`;
}
// items = '<li>1</li><li>2</li><li>3</li>'
Value not set
const arr = [1, 2, 3];
let items;
for (let i = 0; i < arr.length; i++) {
items += `<li>${arr[i]}</li>`;
}
// items = 'undefined<li>1</li><li>2</li><li>3</li>'