Category: JavaScript

Sometimes, we want to replace all instances of character in string in TypeScript.

In this article, we’ll look at how to replace all instances of character in string in TypeScript.

How to replace all instances of character in a string in TypeScript?

To replace all instances of character in string in TypeScript, we can use the string replace method.

For instance, we write

const email = "my.email@email.com";

const re = /\./gi;
const result = email.replace(re, "x");

console.log(result);

to define the re regex with the g flag, which matches all instances of the pattern against the string we call replace with.

Then we call email.replace to match all periods with replace them with 'x'.

Conclusion

To replace all instances of character in string in TypeScript, we can use the string replace method.

Sometimes, we want to fix the "parameter implicitly has an ‘any’ type" error in TypeScript.

In this article, we’ll look at how to fix the "parameter implicitly has an ‘any’ type" error in TypeScript.

How to fix the "parameter implicitly has an ‘any’ type" error in TypeScript?

To fix the "parameter implicitly has an ‘any’ type" error in TypeScript, we can set the noImplicitAny option to false in tsconfig.json.

For instance, we write

{
  "noImplicitAny": false
}

to set the noImplicitAny option to false in tsconfig.json.

Now the "parameter implicitly has an ‘any’ type" error shouldn’t be showing for untyped variables.

Conclusion

To fix the "parameter implicitly has an ‘any’ type" error in TypeScript, we can set the noImplicitAny option to false in tsconfig.json.

Sometimes, we want to add switch statement for a specific type in TypeScript.

In this article, we’ll look at how to add switch statement for a specific type in TypeScript.

How to add switch statement for a specific type in TypeScript?

To add switch statement for a specific type in TypeScript, we can add them as we do with JavaScript.

For instance, we write

interface Action {}

class SpecificAction implements Action {
  kind: "specific";
  payload?: any;
}

class ToggleAction implements Action {
  kind: "toggle";
  toggle: boolean;
}

let action: SpecificAction | ToggleAction;
switch (action.kind) {
  case "specific":
    console.log(action.payload);
    break;
  case "toggle":
    console.log(action.toggle);
    break;
}

to create the action variable that has the SpecificAction | ToggleAction.

So the kind, payload, and toggle values are all valid properties.

We compare the action.kind value with the values listed with case.

Conclusion

To add switch statement for a specific type in TypeScript, we can add them as we do with JavaScript.

Sometimes, we want to get HTMLElement from element with TypeScript.

In this article, we’ll look at how to get HTMLElement from element with TypeScript.

How to get HTMLElement from element with TypeScript?

To get HTMLElement from element with TypeScript, we can cast elements to HTMLElement.

For instance, we write

const nodes = document.querySelectorAll<HTMLElement>("a");

to cast the items in the node list returned by querySelectorAll to HTMLElement.

We can also cast them to more specific element types with

const nodes = document.querySelectorAll<HTMLAnchorElement>("a");

to cast all the elements in the node list to the HTMLAnchorElement type.

Conclusion

To get HTMLElement from element with TypeScript, we can cast elements to HTMLElement.

Sometimes, we want to sort strings descending with TypeScript

In this article, we’ll look at how to sort strings descending with TypeScript.

How to sort strings descending with TypeScript?

To sort strings descending with TypeScript, we can compare strings with comparison operators.

For instance, we write

const sorted: string[] = values.sort((one, two) => (one > two ? -1 : 1));

to call sort with a callback to compare strings one and two.

We return -l to reverse their order if one is bigger than two.

Otherwise, we return 1 to sort them in ascending order.

one and two are both entries in values being iterated through.

Conclusion

To sort strings descending with TypeScript, we can compare strings with comparison operators.