Why is my map() with spread syntax not working?
I'm really not seeing where this is going wrong. I've seen posts of this particular example from O'Reilly's Learning React, by Banks & Porcello. However, the posts seem to work fine, but my example does not. If I have a typo, I don't see it. Where's my flaw? I don't know why I get a null string value instead of "HB Woodlawn"
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport"
content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<meta http-equiv="X-UA-Compatible" content="ie=edge">
<title></title>
<script src="https://unpkg.com/[email protected]/babel.min.js"></script>
</head>
<body>
<script type="text/babel">
// Editing one object in an array of objects
let schools = [
{name: 'Yorktown'},
{name: 'Stratford'},
{name: 'Washington & Lee'},
{name: 'Wakefield'}
];
const editName = (oldName, newName, arr) =>
arr.map(item => {
if (item.name === oldName) {
return {
...item,
name
}
}
else {
return item
}
});
let updatedSchools = editName('Stratford', 'HB Woodlawn', schools);
console.log(updatedSchools[1]); // name: ""
console.log(schools[1]); // name: "Stratford"
</script>
</body>
</html>
Answer
let schools = [
{name: 'Yorktown'},
{name: 'Stratford'},
{name: 'Washington & Lee'},
{name: 'Wakefield'}
];
const editName = (oldName, newName, arr) =>
arr.map(item => {
if (item.name === oldName) {
return {
...item,
name: newName
}
}
else {
return item
}
});
let updatedSchools = editName('Stratford', 'HB Woodlawn', schools);
console.log(updatedSchools[1]); // name: ""
console.log(schools[1]); // name: "Stratford"
You hadn't added the new value for the name, instead had left it empty. Added name:newName