Hey everyone, I’m running into a bit of trouble with my JavaScript code. I’m attempting to use square bracket notation within class methods, but it doesn’t seem to work as I’d expect. I’m able to access object properties fine with this notation, yet when I try to dynamically invoke a method using it, I receive errors.
class MyDemoClass {
constructor() {
this.info = { key: 'example' };
}
showKey() {
console.log(this.info['key']);
}
dynamicCall(methodName) {
console.log(this[methodName]());
}
}
const instance = new MyDemoClass();
instance.showKey(); // This works
instance.dynamicCall('showKey'); // This causes an error
Is there a way to correctly implement this feature? Any guidance would be appreciated!
I’ve encountered this issue before in my projects. Square bracket notation is indeed usable within class methods, but there’s a subtle catch when dynamically invoking methods.
In your dynamicCall method, you’re trying to log the result of the invoked method, which might be undefined. Instead, just call the method directly:
dynamicCall(methodName) {
this[methodName]();
}
This should resolve the error. Remember, when using square brackets for method invocation, the parentheses go outside the brackets.
Also, consider error handling for non-existent methods:
dynamicCall(methodName) {
if (typeof this[methodName] === 'function') {
this[methodName]();
} else {
console.error(`Method ${methodName} not found`);
}
}
This approach has saved me countless headaches in larger applications. Hope this helps!
yea, u can use square brackets in class methods. Your example’s close, but missing parentheses. Try this:
dynamicCall(methodName) {
thismethodName;
}
instance.dynamicCall(‘showKey’);
Should work now. square brackets r super useful for dynamic property/method access. good luck!
Square bracket notation is indeed valid within class methods. Your approach is on the right track, but there’s a small adjustment needed. In the dynamicCall method, you’re attempting to log the result of the method call, which may not always return a value. Instead, simply invoke the method:
dynamicCall(methodName) {
this[methodName]();
}
This modification should resolve the error you’re encountering. It’s worth noting that square bracket notation is particularly useful for scenarios where method names are determined dynamically at runtime. However, exercise caution when using this technique, as it can make code less predictable and harder to maintain if overused. Always ensure that the method being called exists to avoid potential runtime errors.