Initialize your variables first, then compare using if statement and assign new values where necessary . var a = "red"; var b; if(a=="red"){ b="hot"; } else{ b="cold"; }

Nov 11, 2019 · Method 1: If the condition evaluates to true, the value on the left side of the column would be assigned to the variable. If the condition evaluates to false the condition on the right will be assigned to the variable. You can also nest many conditions into one statement.

The if/else statement is a part of JavaScript's "Conditional" Statements, which are used to perform different actions based on different conditions. In JavaScript we have the following conditional statements: Use if to specify a block of code to be executed, if a specified condition is true

Headache example: var foo = 10; function myfunc() { if (foo > 0) { var foo = 0; alert('foo was greater than 0'); } else { alert('wut?'); } } Guess what, we're getting a 'wut?' alert when calling myfunc here.

Use the if statement to specify a block of JavaScript code to be executed if a condition is true. Syntax

Mar 13, 2025 · The var statement declares function-scoped or globally-scoped variables, optionally initializing each to a value.

Start the statement with var and separate the variables by comma: Declare many variables in one statement. Start the statement with let and separate the variables by comma: Using var in a loop: Using let in a loop: var is an ECMAScript1 (JavaScript 1997) feature. It …

Feb 10, 2025 · When a variable is declared using var, it is function-scoped or globally-scoped, depending on where it is declared. Syntax. It declares a variable using var, assigns it a value, and allows it to be re-declared or updated within its scope. 1. Function Scope. Variables declared using var are function-scoped.

Mar 21, 2023 · In programming, we use an if statement when we want our code to make a decision. In this tutorial, we'll deep dive into the JavaScript if statement. Along the way, we'll examine the difference between single equals, double equals, and triple equals. We'll also clarify the meaning of truthy and falsy in JavaScript.

Dec 3, 2008 · Sometimes functions can sneak in largely unnoticed; that's the case with accessor functions. Here's an example: var obj = { value: 0, get f() { return this.value; }, set f(v) { this.value = v; } }; console.log(obj.f); // 0 console.log(typeof obj.f); // "number"