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id	title	isRequired	challengeType
afcc8d540bea9ea2669306b6	Repeat a String Repeat a String	true	5

Description

Repeat a given string str (first argument) for num times (second argument). Return an empty string if num is not a positive number. Remember to use Read-Search-Ask if you get stuck. Write your own code.

Instructions

Tests

tests:
  - text: <code>repeatStringNumTimes("*", 3)</code> should return <code>"***"</code>.
    testString: assert(repeatStringNumTimes("*", 3) === "***", '<code>repeatStringNumTimes("*", 3)</code> should return <code>"***"</code>.');
  - text: <code>repeatStringNumTimes("abc", 3)</code> should return <code>"abcabcabc"</code>.
    testString: assert(repeatStringNumTimes("abc", 3) === "abcabcabc", '<code>repeatStringNumTimes("abc", 3)</code> should return <code>"abcabcabc"</code>.');
  - text: <code>repeatStringNumTimes("abc", 4)</code> should return <code>"abcabcabcabc"</code>.
    testString: assert(repeatStringNumTimes("abc", 4) === "abcabcabcabc", '<code>repeatStringNumTimes("abc", 4)</code> should return <code>"abcabcabcabc"</code>.');
  - text: <code>repeatStringNumTimes("abc", 1)</code> should return <code>"abc"</code>.
    testString: assert(repeatStringNumTimes("abc", 1) === "abc", '<code>repeatStringNumTimes("abc", 1)</code> should return <code>"abc"</code>.');
  - text: <code>repeatStringNumTimes("*", 8)</code> should return <code>"********"</code>.
    testString: assert(repeatStringNumTimes("*", 8) === "********", '<code>repeatStringNumTimes("*", 8)</code> should return <code>"********"</code>.');
  - text: <code>repeatStringNumTimes("abc", -2)</code> should return <code>""</code>.
    testString: assert(repeatStringNumTimes("abc", -2) === "", '<code>repeatStringNumTimes("abc", -2)</code> should return <code>""</code>.');
  - text: The built-in <code>repeat()</code>-method should not be used
    testString: assert(!/\.repeat/g.test(code), 'The built-in <code>repeat()</code>-method should not be used');

Challenge Seed

function repeatStringNumTimes(str, num) {
  // repeat after me
  return str;
}

repeatStringNumTimes("abc", 3);

Solution

function repeatStringNumTimes(str, num) {
  if (num < 0) return '';
  return num === 1 ? str : str + repeatStringNumTimes(str, num-1);
}

repeatStringNumTimes("abc", 3);

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