freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/debugging/catch-use-of-assignment-operator-instead-of-equality-operator.english.md

id, title, challengeType

id	title	challengeType
587d7b85367417b2b2512b38	Catch Use of Assignment Operator Instead of Equality Operator	1

Description

Branching programs, i.e. ones that do different things if certain conditions are met, rely on if, else if, and else statements in JavaScript. The condition sometimes takes the form of testing whether a result is equal to a value. This logic is spoken (in English, at least) as "if x equals y, then ..." which can literally translate into code using the =, or assignment operator. This leads to unexpected control flow in your program. As covered in previous challenges, the assignment operator (=) in JavaScript assigns a value to a variable name. And the == and === operators check for equality (the triple === tests for strict equality, meaning both value and type are the same). The code below assigns x to be 2, which evaluates as true. Almost every value on its own in JavaScript evaluates to true, except what are known as the "falsy" values: false, 0, "" (an empty string), NaN, undefined, and null.

let x = 1;
let y = 2;
if (x = y) {
  // this code block will run for any value of y (unless y were originally set as a falsy)
} else {
  // this code block is what should run (but won't) in this example
}

Instructions

Fix the condition so the program runs the right branch, and the appropriate value is assigned to result.

Tests

tests:
  - text: Your code should fix the condition so it checks for equality, instead of using assignment.
    testString: assert(result == "Not equal!", 'Your code should fix the condition so it checks for equality, instead of using assignment.');
  - text: The condition can use either <code>==</code> or <code>===</code> to test for equality.
    testString: assert(code.match(/x\s*?===?\s*?y/g), 'The condition can use either <code>==</code> or <code>===</code> to test for equality.');

Challenge Seed

let x = 7;
let y = 9;
let result = "to come";

if(x = y) {
  result = "Equal!";
} else {
  result = "Not equal!";
}

console.log(result);

Solution

let x = 7;
let y = 9;
let result = "to come";

if(x === y) {
 result = "Equal!";
} else {
 result = "Not equal!";
}

console.log(result);