Reset the counter back to zero before it begins anew at 1

Question

Reset the counter back to zero before it begins anew at 1

I am looking to create functionality that involves storing the number of read messages in an array. I want to then reset this counter based on the difference between the length of the message array and the current counter value.

this.badgeCount = this.messages.length //5

The this.messages.length value is obtained from the service for each individual message.

Whenever the matMenu is closed, I need to reset the counter to zero and mark all messages as read.

menuClosed(){
 this.badgeCount = 0;

 this.messages.forEach((message: Message){
  message.read = true;
 })

}

The issue I am facing is that the this.messages.length always reflects the actual length, let's say 5. As a result, when a new message arrives, causing the length to increase to 6, the badgeCount also resets to 6 instead of 0. Is there a way to store the read messages in an array and calculate the count based on the total length of messages?

Here is a working sample

javascript angular typescript

Answer 1

Answer №1

To streamline the service, focus solely on counting unread messages as demonstrated in the code snippet below:

this.unreadCount = this.messages.filter((message: Message) {
    return !message.read;
}).length;

Answer 2

To streamline the service, focus solely on counting unread messages as demonstrated in the code snippet below:

this.unreadCount = this.messages.filter((message: Message) {
    return !message.read;
}).length;

Answer 3

Answer №2

It seems like your question may be a bit unclear, but I'll do my best to provide an answer.

If you wish to store read messages in a separate array, you can simply declare the array and add messages to it using the push method.

menuClosed(){
 this.badgeCount = 0;
 var readMessages : Message[];

 this.messages.forEach((message: Message){
  message.read = true;
  readMessages.push(message);
 })

 //You can now access the length of readMessages
}

If you only need the count of read messages without storing them in a separate array...

menuClosed(){
 this.badgeCount = 0;

 this.messages.forEach((message: Message){
  message.read = true;
 })

 //Store the count of read messages in a class variable for future use
 this.readMessages = this.messages.length ;
}

Answer 4

It seems like your question may be a bit unclear, but I'll do my best to provide an answer.

If you wish to store read messages in a separate array, you can simply declare the array and add messages to it using the push method.

menuClosed(){
 this.badgeCount = 0;
 var readMessages : Message[];

 this.messages.forEach((message: Message){
  message.read = true;
  readMessages.push(message);
 })

 //You can now access the length of readMessages
}

If you only need the count of read messages without storing them in a separate array...

menuClosed(){
 this.badgeCount = 0;

 this.messages.forEach((message: Message){
  message.read = true;
 })

 //Store the count of read messages in a class variable for future use
 this.readMessages = this.messages.length ;
}

Reset the counter back to zero before it begins anew at 1

Answer №1

Answer №2

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