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Edeke Emmanuel
Edeke Emmanuel

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Data types conversion in JavaScript

*Changing value from one data types to another *

conversion of the value of the declare variable to a different data types can be done by ensuring that the data type to be converted to, is the one used and begins with a Capital letter. For example:

let year = String(1980); 
console.log(year);  //"1980"
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methods

Generally: let x = Data-types(value);

List of Data-types

  1. Number
  2. String
  3. Boolean e.t.c

JavaScript has some in built conversion one can explore without the use of methods:

let result;
//For example =>
// String conversion
result = '3' + 2;  // "32"
result = '10' + true;  //"10true"

//Number conversion
result = '10' - '2'; // 8 
result = '10' - 2; //8

//NaN conversion
result = 'hello' - 'world'; // NaN 
result = '4' - 'hello'; //NaN

//Boolean conversion
result = '8' - true;  // 7 
result = 4 + true; //5

//Null conversion
result = 15 + null;  // 15
result = 4 - null; //4
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To check what type of data type, make use of typeof

console.log(typeof(num)); //Number

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while with method

/* convert to number */

string can be converted to number using Number keyword even other data types such as boolean and null in JavaScript.
for example:
true is known as 1 while false, empty string "" and null is 0 or empty value.
A text, NaN and undefined will return Not a number NaN
Number Conversion

/* method in Number*/

some specific method can be used to convert one data types to a number. Method like:

1. parseInt()
2. parseFloat()
3. /*unary operator*/ +"" 
4. Math.floor()
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example:
Number Conversion using methods

/* convert to string */

conversion to string is done with String /*or*/ toString(). example:
String Conversion

/* convert to boolean */

empty string, 0, undefined, NaN and null return false when passed with boolean but others return true.
example:
Boolean Conversion

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