freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/rosetta-code/strip-control-codes-and-extended-characters-from-a-string.md

id	title	challengeType
5a23c84252665b21eecc8036	Strip control codes and extended characters from a string	5

Description

The task is to strip control codes and extended characters from a string. In ASCII, the control codes have decimal codes 0 through to 31 and 127. On an ASCII based system, if the control codes are stripped, the resultant string would have all of its characters within the range of 32 to 126 decimal on the ASCII table. On a non-ASCII based system, we consider characters that do not have a corresponding glyph on the ASCII table (within the ASCII range of 32 to 126 decimal) to be an extended character for the purpose of this task.

Instructions

Tests

tests:
  - text: <code>strip</code> should be a function.
    testString: assert(typeof strip == 'function', '<code>strip</code> should be a function.');
  - text: <code>strip("abc")</code> should return a string.
    testString: assert(typeof strip("\ba\\x00b\n\rc\fd\xc3") == 'string', '<code>strip("abc")</code> should return a string.');
  - text: <code>strip("\\ba\\x00b\\n\\rc\\fd\\xc3")</code> should return <code>"abcd"</code>.
    testString: assert.equal(strip("\ba\x00b\n\rc\fd\xc3"), "abcd", '<code>strip("\\ba\\x00b\\n\\rc\\fd\\xc3")</code> should return <code>"abcd"</code>.');
  - text: <code>strip("\\u0000\\n abc\\u00E9def\\u007F")</code> should return <code>" abcdef"</code>.
    testString: assert.equal(strip("\u0000\n abc\u00E9def\u007F"), " abcdef", '<code>strip("\\u0000\\n abc\\u00E9def\\u007F")</code> should return <code>" abcdef"</code>.');
  - text: <code>strip("a\\n\\tb\\u2102d\\u2147f")</code> should return <code>"abdf"</code>.
    testString: assert.equal(strip("a\n\tb\u2102d\u2147f"), "abdf", '<code>strip("a\\n\\tb\\u2102d\\u2147f")</code> should return <code>"abdf"</code>.');
  - text: <code>strip("Français.")</code> should return <code>"Franais."</code>.
    testString: assert.equal(strip("Français."), "Franais.", '<code>strip("Français.")</code> should return <code>"Franais."</code>.');
  - text: <code>strip("123\\tabc\\u0007DEF\\u007F+-*/€æŧðłþ")</code> should return <code>"123abcDEF+-*/"</code>.
    testString: assert.equal(strip("123\tabc\u0007DEF\u007F+-*/€æŧðłþ"), "123abcDEF+-*/", '<code>strip("123\\tabc\\u0007DEF\\u007F+-*/€æŧðłþ")</code> should return <code>"123abcDEF+-*/"</code>.');

Challenge Seed

function strip(s) {
  // Good luck!
}

Solution

function strip(s) {
  return s.split('').filter(function(x) {
    var n = x.charCodeAt(0);

    return 31 < n && 127 > n;
  }).join('');
}