Type Conversions in JavaScript
Most of the time, the functions and operators automatically convert the values given then to the right type. An alert automatically converts any value to a string to show it. Mathematical operations change the importance of numbers.
JavaScript is a client-side, object-based scripting language that is used to control and verify client-side data. JavaScript, earlier known as LiveScript, has been developed by Netscape and Sun Microsystems. Are you looking for Javascript Training in Chennai? Take a step into FITA, Enhance your knowledge with us for employability. FITA is the best leading institution for Javascript Course in Chennai.
String Conversion
String conversion happens, when we need the string form of a value. For example, the alert(value) does it to show the value. We can also call the String(value) function to convert a value to a string.
let value= true;
alert(typeof value);//boolean
value=String(value); // now value is a string "true"
alert(typeof value); // string
String conversion is mostly obvious. A false becomes "false", null becomes "null", etc...
Numeric Conversion
Numeric conversion happens for mathematical purposes and expressions automatically.
For example, when division/ is applied to non-numbers:
alert( "6" / "2" ); // 3, string are converted to numbers. we can also use the Number(value) function to explicity convert a value to a number.
let str = "123";
alert(typeof str); // string
let num = Number(str); // becomes a number 123
alert(typeof num); // number
Explicit conversion is needed when we read a value from a string-based source like a text form but require a number to be entered. If the string is not a valid number, the result of such a conversion is NaN.
let age= Number("an arbitrary string instead of a number");
alert(age); // NaN, change failed
Examples:
alert( Number(" 123 ") ); // 123
alert( Number("123z") ); // NaN (error reading a number at "z")
alert( Number(true) ); // 1
alert( Number(false) ); // 0
Please note that null and irregular function differently here: null becomes zero while undefined becomes NaN. Most mathematical engineers also make such a change.
Boolean conversion
Boolean conversion is the simplest one.
It may happen in logical operations (later we’ll meet condition tests and other similar things), but can also be performed explicitly with a call to boolean(value).
The conversion rule
Values that are intuitively "empty", like, an empty string, null, undefined, and NaN become false. Other values become true.
For instance:
alert( Boolean(1) ); // true
alert( Boolean(0) ); // false
alert( Boolean("hello") ); // true
alert( Boolean("") ); // false
JavaScript is commonly used as a part of web pages. It is an interpreted programming language with Object-Oriented capabilities. Are you looking for Javascript Training in Bangalore? Take a step into FITA, Enhance your knowledge with us for employability. FITA is the best leading institution for Javascript Course in Bangalore. | Javascript Coaching in Bangalore |
- Art
- Causes
- Crafts
- Dance
- Drinks
- Film
- Fitness
- Food
- Jogos
- Gardening
- Health
- Início
- Literature
- Music
- Networking
- Outro
- Party
- Religion
- Shopping
- Sports
- Theater
- Wellness