Introduction to TypeScript Cast Object
The typescript cast object is one of the features for converting the one type of variable values. Data types may be integer, string, float, double values or it may be some interfaces are to convert it. If the user has written some functions based on the default classes we can call the methods for the specific classes by using the object reference. So we are unable to use the object reference in all the sections based on their needs. we used a cast object to convert the object into another type with some references.
Syntax of TypeScript Cast Object
The Typescriptis one of the web-based languages before JavaScript. we used typescript it is mainly referred to the type of conversions that are for to convert one data type to the other data types. Here we used assertions to enable to override the default behaviors and also type assertions are fully compiled time construct and it’s one of the ways to analyze the codes.
Code:
class classname{
constructor()
{
--some logics—
{
function()
{
}
window.onload=() = >
{
variablename = new classname();
variablename.function();
};
The above code is the basic syntax for to traverse the downcasting in the application. Here we used some class names for to construct the applications and also we can create the instance for calling the classname so it will raise it from the upward casting to downward casting. Like that we used n number of type casting will be applicable for this script we can convert the object type to interface type etc these are some frequency type casting performed by the user end.
How Cast Object Work in TypeScript?
The Typescript generally it converts one data type to another data type by using the cast operation. We can convert all types of datas are converted from one type to another type like that cast object is one of the features for to convert the object type of values to another type. We can also cast some generic type of objects to the custom object types by using the <> symbol or it’s a keyword for converting the object to another type like array etc. Generally, the object has and its already declared the multiple properties and their attributes by using some methodology like key-value pairs. When we used an object in the class the variable has the array datatype then we can store and retrieve the datas by using the keys like object.keys(), object.values(). The keys will be retrieved by using the method called object.keys() and it always returns the array return type with keys. By using the map() method we can define the values incallbackconcept for storing and retrieving the datas from the backend. If we want to cast the object to string data types by using toString() method we can change the object type to a string data type. We can also cast the object type to jsonby using json.parse() method we can get only the plain objects and it not used on the class object. Mainly we used class objects with the help of constructors it’s creating and it will be defined with properties, constructors, and pre-defined methods.
Examples of TypeScript Cast Object
Following are the examples are given below:
Example #1
Code:
const eg = {
'demo': {type: 'string'},
'demo1': {type: 'string'},
'demo2': {type: 'string'},
'demo3': {type: 'string'},
'demo4': {type: 'string'},
'demo5':{type:'string'},
'demo6':{type:'string'}
};
let vars = [];
for(let vars1 in eg) {
vars.push({[vars1] : eg[vars1]});
}
console.log("Welcome To My Domain your first object variable is:", eg);
console.log("Thanks user after converting object to arrays your variable is:", vars);
function erg(labeledObj: { value: string }) {
console.log(labeledObj.value);
}
let vars2 = { key: 'demo', value: "Thanks users have a nice day" };
erg(vars2);
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Output:
The above example we can get the object type to array types here we can used function with default keywords, variables with data types. Mainly we used string data type for all the keys here we used ‘demo to demo6’ these are the keys will be handling the type like string so the keys are must be unique ID so it does not accept duplicates for any of the sections in the script. By using for loop we can iterate the values and store it on the separate variable like let it is a local storage variable it does not use on the global type.
Example #2
Code:
var example = {
siva: { first:6245, second:1725},
raman: { first:6245, second:1725,five:'qjwkgje jweg wqegj wjeg kwjeg wejkg wejkg kwhe kwhej'},
sivaraman: { first:6245, second:1725,four:'jges jwge wjge wjeg kwjegr jkwegr jkewgr'},
kweg: { first:6245, second:1725},
ksdhjg: { first:6245, second:1725,four:'jgsd jags jsd g wjeg qwkjeg wekjg kqweg kqwge'},
kjlsldj: { first:6245, third:827,four:'jsgd34 asjkdgf jgds wjhg jweg kwjge kweg kwejg'},
}
let vars = [];
Object.keys(example).map(function(key){
vars.push({[key]:example[key]})
return vars;
});
console.log('Welcome To My Domian Object of the people are=',example)
console.log('After converting the people object to array is=',vars)
Output:
In the second example we used object casting by using the keys() method we can declare the variable with key-value type the key must be a unique one and the value may be any type. Using Object.keys() method we can iterate the value and traverse the array elements in upcastingi.e) upcasting to downcasting. Finally, it will return the array as the return type.
Example #3
Code:
class demo {
sample:string;
constructor(sample1:string) {
this.sample = sample1
}
views():void {
console.log("Welcome To My Domain:"+this.sample)
}
}
class demo1 extends demo{
example()
{
console.log("your third example this thanks")
}
}
var vars2 = new demo("Sivaraman")
console.log("Have a Nice Day user: "+vars2.sample)
vars2.views();
function testss(d:demo) {
if (d instanceof demo1) {
d.example();
}
}
Output:
The final example we used class with methods. We can implement the parent child relationships that is we have to extend the parent class to child class and we have created the instance or object of the parent class var reference= new example(); this object reference is meant by the downcasting the code snippets and traverses from upward to downward casting by using the console.log() statement we can print the output on the console screen.
Conclusion
In the concluded part typescript is the superscript of javascript. It will be more or less equal for the javascript but it will be executed at the compile time. Typescript casting is a most important concept when we use javascript we are unable to cast the variables but in typescript, we can cast it from object to class, object to the interface, object to strings, etc based on the user requirement we can cast it.
Recommended Articles
This is a guide to TypeScript Cast Object. Here we also discuss the introduction and how cast objects work in typescript? along with different examples and their code implementation. You may also have a look at the following articles to learn more –
