JavaScript - IF condition - Part 2

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What are Truthy and Falsey states?

The If condition executes when an expression returns Truthy value. If condition will execute else statement when the expression returns Falsey value.

A Truthy value is a value that is considered "true" when used in a boolean context.

A Falsey value is a value that is considered "false" when used in a boolean context.

Use cases: Truthy and Falsey values

Case 1: If the condition is a boolean true - it is considered to be Truthy.

if (true)
    console.log("Truthy value - true");

Case 2: If the conditional expression is {} (empty object). It is considered a Truthy value.

if({})
    console.log("Truthy value - {}");

Case 3: If the conditional expression is [] (empty array). It is considered a Truthy value.

if([])
 console.log("Truthy value- []");

Case 4: If the conditional expression is a positive number. It is considered a Truthy value.

if(55)
 console.log("Truthy value - 55");

Case 5: If the conditional expression is 0 within quotes(e.g "0"). It is considered a Truthy value. It is nothing but a string.

if("0") 
 console.log("Truthy value - '0'");

Case 6: If the conditional expression is 0. It is considered a Falsey value.

if(0) 
  console.log("Truthy value - 0");
else
  console.log("Falsey value - 0");

Case 7: If the conditional expression is false. It is considered a Falsey value.

if(false)
    console.log("Truthy value - false");
else
    console.log("Falsey value - false");

Case 8: If the conditional expression is "false" (within quotes). It is considered a Truthy value.

if("false")
  console.log("Truthy value - 'false'");

Case 9: If the conditional expression is an object e.g new Date(). It is considered a Truthy value.

if (new Date())
    console.log("Truthy value - new Date()");

Case 10: If the conditional expression is a negative number. It is considered a Truthy value.

if(-200)
    console.log("Truthy value : -200");

Case 11: If the conditional expression is a bigint. It is considered a Truthy value.

if(999n)
    console.log("Truthy value - 999n")

Case 12: If the conditional expression is a fractional value. It is considered a Truthy value.

if(343.114)
    console.log("Truthy value - 343.114");

Case 13: If the conditional expression is a negative fractional value. It is considered a Truthy value.

if(-2343.14)
    console.log("Truthy value : -2343.14);

Case 14: If the conditional expression is Infinity. It is considered a Truthy value.

if(Infinity)
    console.log("Truthy value - Infinity");

Case 15: If the conditional expression is negative Infinity. It is considered a Truthy value.

if (-Infinity)
    console.log("Truthy value : -Infinity);

Complete Code Listing

/*
Author : Mahavir DS Rathore
Objective : Understanding 'if condition' behaviour  with -- truthy  & falsey values 
*/

// a truthy value is a value that is considered true when used in a Boolean context 
// a falsy value is a value that is considered false when used in a Boolean context 

if (true)  // truthy value
    console.log("true");

if ({}) // truthy value
    console.log("{}");

if ([]) // truthy value
    console.log("[]");

if (55) // truthy value
    console.log("42");

if ("0") // truthy value
    console.log("0");


if(0)    // falsey value
    console.log("true");
else
   console.log("false"); // false

if ("false") // truthy value
    console.log("false");


if(false)     // falsey value 
    console.log("true");
 else
   console.log("false"); // false

 if (new Date()) // truthy value
    console.log("new Date()");

if (-89) // truthy value
    console.log("-42");

if (90n) // truthy value
    console.log("12n");

if (343.114) // truthy value
    console.log("3.14");

if (-2343.14) // // truthy value
    console.log("-3.14");

if (Infinity) // truthy value
    console.log("Infinity");

if (-Infinity) // truthy value
    console.log("-Infinity");

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