freeCodeCamp/curriculum/challenges/english/02-javascript-algorithms-and-data-structures/basic-javascript/replacing-if-else-chains-with-switch.english.md

id	title	challengeType
56533eb9ac21ba0edf2244e0	Replacing If Else Chains with Switch	1

Description

If you have many options to choose from, a switch statement can be easier to write than many chained if/else if statements. The following:

if (val === 1) {
  answer = "a";
} else if (val === 2) {
  answer = "b";
} else {
  answer = "c";
}

can be replaced with:

switch(val) {
  case 1:
    answer = "a";
    break;
  case 2:
    answer = "b";
    break;
  default:
    answer = "c";
}

Instructions

Change the chained if/else if statements into a switch statement.

Tests

tests:
  - text: You should not use any <code>else</code> statements anywhere in the editor
    testString: assert(!/else/g.test(code), 'You should not use any <code>else</code> statements anywhere in the editor');
  - text: You should not use any <code>if</code> statements anywhere in the editor
    testString: assert(!/if/g.test(code), 'You should not use any <code>if</code> statements anywhere in the editor');
  - text: You should have at least four <code>break</code> statements
    testString: assert(code.match(/break/g).length >= 4, 'You should have at least four <code>break</code> statements');
  - text: <code>chainToSwitch("bob")</code> should be "Marley"
    testString: assert(chainToSwitch("bob") === "Marley", '<code>chainToSwitch("bob")</code> should be "Marley"');
  - text: <code>chainToSwitch(42)</code> should be "The Answer"
    testString: assert(chainToSwitch(42) === "The Answer", '<code>chainToSwitch(42)</code> should be "The Answer"');
  - text: "<code>chainToSwitch(1)</code> should be \"There is no #1\""
    testString: "assert(chainToSwitch(1) === \"There is no #1\", '<code>chainToSwitch(1)</code> should be \"There is no #1\"');"
  - text: <code>chainToSwitch(99)</code> should be "Missed me by this much!"
    testString: assert(chainToSwitch(99) === "Missed me by this much!", '<code>chainToSwitch(99)</code> should be "Missed me by this much!"');
  - text: <code>chainToSwitch(7)</code> should be "Ate Nine"
    testString: assert(chainToSwitch(7) === "Ate Nine", '<code>chainToSwitch(7)</code> should be "Ate Nine"');
  - text: <code>chainToSwitch("John")</code> should be "" (empty string)
    testString: assert(chainToSwitch("John") === "", '<code>chainToSwitch("John")</code> should be "" (empty string)');
  - text: <code>chainToSwitch(156)</code> should be "" (empty string)
    testString: assert(chainToSwitch(156) === "", '<code>chainToSwitch(156)</code> should be "" (empty string)');

Challenge Seed

function chainToSwitch(val) {
  var answer = "";
  // Only change code below this line

  if (val === "bob") {
    answer = "Marley";
  } else if (val === 42) {
    answer = "The Answer";
  } else if (val === 1) {
    answer = "There is no #1";
  } else if (val === 99) {
    answer = "Missed me by this much!";
  } else if (val === 7) {
    answer = "Ate Nine";
  }

  // Only change code above this line
  return answer;
}

// Change this value to test
chainToSwitch(7);

Solution

function chainToSwitch(val) {
  var answer = "";

  switch(val) {
    case "bob":
      answer = "Marley";
      break;
    case 42:
      answer = "The Answer";
      break;
    case 1:
      answer = "There is no #1";
      break;
    case 99:
      answer = "Missed me by this much!";
      break;
    case 7:
      answer = "Ate Nine";
  }
  return answer;
}