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I am trying to instantiate LinkedObject class using above mentioned interface methods:

TravelClientFormPopulator.ts

class TravelClientFormPopulator {
    public populateComboBoxUsingDTOs(dataObjects: Array<DTO>, comboBoxID: string): void {
        // Get the combo box
        var selectElement = <HTMLSelectElement> document.getElementById(comboBoxID);
        // Reset the options 
        selectElement.options.length = 0;
        var linkedObjectsToAdd: LinkedObject[] = new Array<LinkedObject>();
        var defaultLinkedObject: LinkedObject = new LinkedObject("Not Selected", 0);
        linkedObjectsToAdd.push(defaultLinkedObject);
        for (var i = 0; i < dataObjects.length; i++) {
            var value: string = dataObjects[i].getValue; // Error here
            var id: number = dataObjects[i].getId; // And here
            var linkedObject: LinkedObject = new LinkedObject(value, id);
Any help will be highly appreciated. 
                It's useful to understand what the error is saying to help you in future too.  Type '() => string' is not assignable to type 'string'. is basically saying in this instance "A function that returns a string is not assignable to a variable of type string"  Once you read () => string correctly it should all make sense.  If it was pure JS you wouldn't have got an error and your variable would have been pointing to a function instead of the value returned and it would have been even harder to track down what's going on.
– Andrew Wynham
                Dec 23, 2016 at 14:54
For what it worth, if anyone has this problem only in VSCode, just restart VSCode and it should fix it. Sometimes, Intellisense seems to mess up with imports or types. 
Related to Typescript: Argument of type 'RegExpMatchArray' is not assignable to parameter of type 'string'
                Alternatively you can enter the command pallet with ctrl + shift + p, then search for and select Typescript: Restart TS server.
– devklick
                Aug 18, 2022 at 11:04
                I had this same problem with IntelliJ.  Invalidating caches and restarting cured it there too.
– Jason McVetta
                Apr 6 at 18:54
  
First Check you compiler version, Download latest Typescript compiler
  to support ES6 syntaxes
  
typescript still produces output even with typing errors this doesn't
  actually block development,
When you see these errors Check for Syntaxes in initialization or when Calling these methods or variables,

Check whether the parameters of the functions are of wrong data Type,you initialized as 'string' and assigning a 'boolean' or 'number'
For Example
 private errors: string;
    //somewhere in code you assign a boolean value to (string)'errors'
    this.errors=true
    this.error=5
 private values: Array<number>;    
    this.values.push(value);  //Argument of type 'X' is not assignable to parameter of type 'X'
The Error message here is because the Square brackets for Array Initialization is missing, It works even without it, but VS Code red alerts.
private values: Array<number> = [];    
this.values.push(value);
Note:

Remember that Javascript typecasts according to the value assigned, So typescript notifies them but the code executes even with these errors highlighted in VS Code
 var a=2;
 typeof(a) // "number"
 var a='Ignatius';
 typeof(a) // "string"
I'm doing angular 2 and typescript and I didn't realize I had a space in my arrow notation
I had .map(key = >
instead of .map(key => 
Definitely keep your eyes open for stupid syntax errors
  let accessToken = res;
  localStorage.setItem(LocalStorageConstants.TOKEN_KEY, accessToken);
given error Argument of type '{}' is not assignable to parameter of type 'string'.
success Code : 
  var accessToken:any = res;
  localStorage.setItem(LocalStorageConstants.TOKEN_KEY, accessToken);
we create var type variable then use variable type any and resolve this issue.
any = handle any type of value so that remove error.
                setting the type to any is going back to weak typing your code and actually makes it easier for typed errors to crop up
– twildeman
                Jun 30, 2020 at 14:07
.then((error: any, response: any) => {
  console.info('document error: ', error);
  console.info('documenr response: ', response);
  return new MyModel();
on this case making parameters optional would make ts stop complaining
.then((error?: any, response?: any) => {
For scenarios where this error could not be avoided, we can @ts-ignore the error. 

In my case I had to pass a string param to isNaN whose ts definition only allow param of number type.
// @ts-ignore: Argument of type 'string' is not assignable to parameter of type 'number'.
 if (isNaN(myParam)) { // myParam is of string type 
      throw new Error('myPram should be a number');
// but isNaN can accept string params too in javascript
isNaN(123) //false
isNaN('123') //false
isNaN(NaN) //true
isNaN('NaN') //true
                We are using shared layers approach for node lambda written in typescript and faced an error for the type and this solution really worked well.
– YG Abhi
                May 11, 2022 at 18:28
This problem basically comes when your compiler gets failed to understand the difference between cast operator of the type string to Number.
you can use the Number object and pass your value to get the appropriate results for it by using Number(<<<<...Variable_Name......>>>>) 
        
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