Javascript Introduction

JS Type Conversion


In programming, type conversion is the process of converting data of one type to another, facilitating various operations and manipulations within code. JavaScript supports two types of type conversion: implicit and explicit.

JavaScript Implicit Conversion

In JavaScript, implicit conversion occurs automatically in certain situations, where the interpreter converts one data type to another as needed. Example 1: Implicit Conversion to String

let result;

result = '3' + 2; 
console.log(result); // "32"

result = '3' + true; 
console.log(result); // "3true"

Example 2: Implicit Conversion to Number

let result;

result = '4' - '2'; 
console.log(result); // 2

result = '4' * 2;
console.log(result); // 8

Example 3: Non-numeric String Results to NaN

let result;

result = 'hello' - 'world';
console.log(result); // NaN

JavaScript Explicit Conversion

Explicit conversion, also known as type casting, involves manually converting data from one type to another using built-in methods. Example 1: Convert to Number Explicitly

let result;

result = Number('324');
console.log(result); // 324

result = Number(true);
console.log(result); // 1

Example 2: Convert to String Explicitly

let result;

result = String(324);
console.log(result); // "324"

result = String(true);
console.log(result); // "true"

Example 3: Convert to Boolean Explicitly

let result;

result = Boolean('');
console.log(result); // false

result = Boolean(324);
console.log(result); // true

JavaScript Type Conversion Table

Here's a table summarizing the conversion of different values to String, Number, and Boolean in JavaScript:

 

Value String Conversion Number Conversion Boolean Conversion
1 "1" 1 true
0 "0" 0 false
"1" "1" 1 true
"0" "0" 0 true
"ten" "ten" NaN true
true "true" 1 true
false "false" 0 false
null "null" 0 false
undefined "undefined" NaN false
'' "" 0 false
' ' " " 0 true

Understanding these conversion mechanisms is crucial for writing robust and predictable JavaScript code.