freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/use-the-parseint-function-with-a-radix.english.md

id	title	challengeType
587d7b7e367417b2b2512b22	Use the parseInt Function with a Radix	1

Description

The parseInt() function parses a string and returns an integer. It takes a second argument for the radix, which specifies the base of the number in the string. The radix can be an integer between 2 and 36. The function call looks like: parseInt(string, radix); And here's an example: var a = parseInt("11", 2); The radix variable says that "11" is in the binary system, or base 2. This example converts the string "11" to an integer 3.

Instructions

Use parseInt() in the convertToInteger function so it converts a binary number to an integer and returns it.

Tests

tests:
  - text: <code>convertToInteger</code> should use the <code>parseInt()</code> function
    testString: assert(/parseInt/g.test(code), '<code>convertToInteger</code> should use the <code>parseInt()</code> function');
  - text: <code>convertToInteger("10011")</code> should return a number
    testString: assert(typeof(convertToInteger("10011")) === "number", '<code>convertToInteger("10011")</code> should return a number');
  - text: <code>convertToInteger("10011")</code> should return 19
    testString: assert(convertToInteger("10011") === 19, '<code>convertToInteger("10011")</code> should return 19');
  - text: <code>convertToInteger("111001")</code> should return 57
    testString: assert(convertToInteger("111001") === 57, '<code>convertToInteger("111001")</code> should return 57');
  - text: <code>convertToInteger("JamesBond")</code> should return NaN
    testString: assert.isNaN(convertToInteger("JamesBond"), '<code>convertToInteger("JamesBond")</code> should return NaN');

Challenge Seed

function convertToInteger(str) {

}

convertToInteger("10011");

Solution

function convertToInteger(str) {
  return parseInt(str, 2);
}