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Himanshupal0001
Himanshupal0001

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Datatype Conversion in Js!!!

Hi folks, Today we gonna talk about datatype conversion.
Datatype conversion is basically converting one datatype in another. For example: String -> number or vice-versa.

//type conversion and coercion

let myVar = 34;
console.log(myVar, (typeof myVar));
myVar = String(34); //datatype conversion
console.log(myVar, (typeof myVar));

let booleanVar = true;
console.log(booleanVar, (typeof booleanVar));
booleanVar = Number(true); //this will give 1 as return value because true = 1, false = 0 by default
console.log(booleanVar, (typeof booleanVar));

let arr = [1,2,3,4,5];
console.log(arr, arr.length, (typeof arr) );
arr = String([1,2,3,4,5]);
console.log(arr, arr.length, (typeof arr));


//also can use toString() funtion to convert any datatype to string
let i = 20;
console.log(i, (typeof i));
console.log(i.toString(), (typeof i));//idk why in console it still giving datatype number
//But as you can see in console line 22 already converted to string
//Note* purple color in console shows number value while white color is for string

//Converting to number
let str = "3454";
console.log(str, (typeof str));
str = Number(str);//also pass the variable instade of value
console.log(str, (typeof str));

let str1 = "3456f"
console.log(str1, (typeof str1));
str1 = Number(str1);
console.log(str1, (typeof str1));//This line will give "NaN" as aoutput means not a number


//parseInt
let number = 34.141;
console.log(number, (typeof number));
number = parseInt(number); //parsing number in integer
console.log(number, (typeof number));



//parseFloat
let number1 = 34.434;
console.log(number1, (typeof number1));
number = parseFloat(number1); //parsing number in float
console.log(number1, (typeof number1));

//toFixed function

let numberVar = 30.087;
console.log(numberVar.toFixed(), (typeof numberVar));//by default 0 decimal number will show
console.log(numberVar.toFixed(6), (typeof numberVar)); //six decimal number will show


//Coercion

let mystr = "3454";
let mynum = 45;

console.log(mystr + mynum);

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Type conversion is very important part of programming that every developer should know about this.

For example you created a form which is accepting only integer values from frontend but you want everything in string from backend. In such scenarios type conversion would be very useful.

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