All watchers can receive a method name instead of functions, preventing you from writing duplicated code. This will help you avoid re-writing the same code, or checking for values and passing them to the functions:
<script>
export default {
watch: {
myField: 'myFunction',
},
data: () => ({
myField: '',
}),
methods: {
myFunction() {
console.log('Watcher using method name.');
},
},
};
</script>