# db.command.set
Update command. Sets the value of a field to be equal to the specified value.
Function signature:
function set(value: any): Command
Compared with the method in which pure JS objects are imported, this method has an advantage of specifying the value of a field to be equal to one object:
// In the following method, only the style.color is updated to red, and the style is not updated to { color: 'red' }, without affecting other fields in the style.
db.collection('todos').doc('doc-id').update({
data: {
style: {
color: 'red'
}
}
})
// In the following method, the style is updated to { color: 'red', size: 'large' }.
db.collection('todos').doc('doc-id').update({
data: {
style: _.set({
color: 'red',
size: 'large'
})
}
})