title: What are JavaScript's builtin strings?
body: <p><em>this question is difficult to summarize in a question title</em></p>
  
  <p><strong>UPDATE</strong>
  I created a JSFiddle that builds an obfuscated string out of your input based on the letters extracted from this question: You can access it <a href="http://jsfiddle.net/w9rFF/14/" rel="noreferrer">here</a>, or would a <a href="http://bl.ocks.org/jasonsperske/5400283" rel="noreferrer">gist</a> be easier?</p>
  
  <p>I recently came across a fun bit of obfuscated JavaScript in <a href="https://stackoverflow.com/users/1249581/vision">this profile</a> that looks like this:</p>
  
  <pre><code>javascript:[[]+1/!1][1^1][1&gt;&gt;1]+({}+[])[1&lt;&lt;1^11&gt;&gt;1]+([]+!!-
  [])[1&lt;&lt;1]+[/~/+{}][+!1][-~1&lt;&lt;1]+([]+/-/[(!!1+[])[1&gt;&gt;1]+(!!1
  +[])[1&lt;&lt;1^1]+(!1+[])[1|1&lt;&lt;1]+(!!1+[])[1^1]])[1^11&lt;&lt;1]+([,][
  ~1]+[])[1-~1]+[[]+{}][!1.1%1][11111.1%11.1*111e11|!1]+(/1/+
  1/[1&lt;1][1%1])[1^11]+[[],[]+{}][1][+1]+(/&lt;&lt;/[1]+[])[1/1.1&amp;1]
  </code></pre>
  
  <p>Sorry to ruin the surprise but when this is evaluated it returns this:</p>
  
  <pre><code>"I love you" in Chrome
  "I lone you" In Firefox
  "I lo[e you" in IE10
  </code></pre>
  
  <p>The way this works when broken out, is to generate a series of messages and to pull letters out of them like so (using the "I" as an example):</p>
  
  <pre><code>[]+1/!1
  returns
  "Infinity"
  then
  [[]+1/!1]
  creates this array:
  ["Infinity"]
  then
  [[]+1/!1][1^1]
  Takes the first (1^1 == 0) element of that array
  "Infinity"
  finally
  [[]+1/!1][1^1][1&gt;&gt;1]
  Takes the first (1&gt;&gt;1 == 0) char of that string
  "I"
  </code></pre>
  
  <p>Other strings that are generated include:</p>
  
  <pre><code>({}+[])       -&gt; "[object Object]" (where the space comes from)
  ([]+!!-[])    -&gt; "false" (used for it's "l")
  [/~/+{}][+!1] -&gt; "/~/[object Object]" (this is used for an "o")
  (/&lt;&lt;/[1]+[])  -&gt; "undefined"
  </code></pre>
  
  <p>I was interested in finding a replacement for the "n" and "[" and came up with this:</p>
  
  <pre><code>String.fromCharCode(('1'.charCodeAt(0)&lt;&lt;1)+(10&lt;&lt;1))
  </code></pre>
  
  <p>Which I feel in in the spirit of using 1's and 0's, but violates one of the more elegant aspects of the original code which is the appearance of having nothing to do with strings at all.  Does anyone else have an idea of how to generate a "v" that is in keeping with the original obfuscated code?</p>
  
  <p><strong><em>Here is some extra information that was found after many talented JavaScript programers took a deeper look at this</em></strong></p>
  
  <p>Firefox returns "I lone you" Because of this line:</p>
  
  <pre><code>([]+/-/[(!!1+[])[1&gt;&gt;1]+(!!1+[])[1&lt;&lt;1^1]+(!1+[])[1|1&lt;&lt;1]+(!!1+[])[1^1]])[1^11&lt;&lt;1]+
  </code></pre>
  
  <p><code>[1^11&lt;&lt;1]</code> trims a specific character from this:</p>
  
  <pre><code>([]+/-/[(!!1+[])[1&gt;&gt;1]+(!!1+[])[1&lt;&lt;1^1]+(!1+[])[1|1&lt;&lt;1]+(!!1+[])[1^1]])
  </code></pre>
  
  <p>Which evaluates to this:</p>
  
  <pre><code>"function test() {
      [native code]
  }"
  </code></pre>
  
  <p>Which looks like we might have our "V"!!!</p>
  
  <p>Chrome returns "I love you", because the same code returns this:</p>
  
  <pre><code>"function test() { [native code] }"
  </code></pre>
  
  <hr>
  
  <p>Before the question is closed for questionable connection with "a real programming issue", I thought I'd add a summarized solution that builds on <a href="https://stackoverflow.com/a/15981930/16959">@Supr's</a>, <a href="https://stackoverflow.com/a/15980008/16959">@Cory's</a> and <a href="https://stackoverflow.com/a/15978467/16959">@alpha123's</a>, behold:</p>
  
  <pre><code>alert([[]+1/!1][1^1][1&gt;&gt;1]+({}+[])[1&lt;&lt;1^11&gt;&gt;1]+(
  []+!!-[])[1&lt;&lt;1]+[/~/+{}][+!1][-~1&lt;&lt;1]+[([]+/-/[(
  !!1+[])[1&gt;&gt;1]+(!!1+[])[1&lt;&lt;1^1]+(!1+[])[1|1&lt;&lt;1]+(
  !!1+[])[1^1]])[1+(1^(11+1+1)&lt;&lt;1)],([]+/-/[(!!1+[
  ])[1&gt;&gt;1]+(!!1+[])[1&lt;&lt;1^1]+(!1+[])[1|1&lt;&lt;1]+(!!1+[
  ])[1^1]])[1^11&lt;&lt;1],([]+/-/[(!!1+[])[1&gt;&gt;1]+(!!1+[
  ])[1&lt;&lt;1^1]+(!1+[])[1|1&lt;&lt;1]+(!!1+[])[1^1]])[1^(11
  +1+1)&lt;&lt;1]][((([]+/-/[(!!1+[])[1&gt;&gt;1]+(!!1+[])[1&lt;&lt;
  1^1]+(!1+[])[1|1&lt;&lt;1]+(!!1+[])[1^1]])[(1&lt;&lt;1&lt;&lt;1&lt;&lt;1
  )+1&lt;&lt;1]==({}+[])[1^1])*1)+((([]+/-/[(!!1+[])[1&gt;&gt;
  1]+(!!1+[])[1&lt;&lt;1^1]+(!1+[])[1|1&lt;&lt;1]+(!!1+[])[1^1
  ]])[(1^11&lt;&lt;1)-1]==({}+[])[1^1])&lt;&lt;1)]+([,][~1]+[]
  )[1-~1]+[[]+{}][!1.1%1][11111.1%11.1*111e11|!1]+
  (/1/+1/[1&lt;1][1%1])[1^11]+[[],[]+{}][1][+1]+(/&lt;&lt;/
  [1]+[])[1/1.1&amp;1])
  </code></pre>
  
  <p>Given the complexity of the code and the message it produces it's almost like the JavaScript engine is telling how special you make it feel :)</p>