I defined a `const` within the `this.api.getApi().subscribe(({tool,beauty})` function. Now I'm trying to figure out how to execute it within an `if`

Question

I defined a `const` within the `this.api.getApi().subscribe(({tool,beauty})` function. Now I'm trying to figure out how to execute it within an `if`

I've recently set up a const variable within

this.api.getApi().subscribe(({tool,beuty})

. Now, I'm trying to figure out how to run it within an if statement, just like this:

if (evt.index === 0) {aa}

I plan on adding more similar lines and I need to execute them with different if statements.

this.beu=beuty.slice(0,this.i+=15);

Any suggestions on a better approach to achieve this?

Here is the code snippet:

  onScrollDown(evt:any ) {     
    setTimeout(()=>{      
        this.api.getApi().subscribe(({tool,beuty}) => {       
            const aa=this.beu=beuty.slice(0,this.i+=15);
        })
    if (evt.index === 0) {aa}       
    },1000);
  }

javascript angular typescript

Answer 1

Answer №1

When using const, a variable declared within a block scope cannot be accessed outside of that block. If you try to access it outside of its scope, you will encounter a ReferenceError.

function foo() {
    const bar = "bar";
}
console.log(bar);

Similarly, in the code snippet below, you cannot use aa outside of the callback function passed to this.api.getApi().subscribe().

If you wish to use aa outside of the callback function, you should declare it using let instead of const. Here's an updated version of the code:


  onScrollDown(evt:any) {
      
    setTimeout(() => {

        // Add this:
        let aa;
         
        this.api.getApi().subscribe(({tool,beuty}) => {
            // Change this:
            aa=this.beu=beuty.slice(0,this.i+=15);
        })
     
        if (evt.index === 0) {aa}
            
    }, 1000);
   

  }

I hope this explanation clarifies the issue. Without the complete script, I cannot guarantee its functionality.

Answer 2

When using const, a variable declared within a block scope cannot be accessed outside of that block. If you try to access it outside of its scope, you will encounter a ReferenceError.

function foo() {
    const bar = "bar";
}
console.log(bar);

Similarly, in the code snippet below, you cannot use aa outside of the callback function passed to this.api.getApi().subscribe().

If you wish to use aa outside of the callback function, you should declare it using let instead of const. Here's an updated version of the code:


  onScrollDown(evt:any) {
      
    setTimeout(() => {

        // Add this:
        let aa;
         
        this.api.getApi().subscribe(({tool,beuty}) => {
            // Change this:
            aa=this.beu=beuty.slice(0,this.i+=15);
        })
     
        if (evt.index === 0) {aa}
            
    }, 1000);
   

  }

I hope this explanation clarifies the issue. Without the complete script, I cannot guarantee its functionality.

I defined a `const` within the `this.api.getApi().subscribe(({tool,beauty})` function. Now I'm trying to figure out how to execute it within an `if`

Answer №1

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