tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

exp-operator-precedence-update-expression-semantics.js (1641B)

      1 // Copyright (C) 2016 Rick Waldron. All rights reserved.
      2 // This code is governed by the BSD license found in the LICENSE file.
      3 
      4 /*---
      5 author: Rick Waldron
      6 esid: sec-update-expressions
      7 description: Exponentiation Operator expression precedence of update operators
      8 info: |
      9  ExponentiationExpression :
     10    ...
     11    UpdateExpression `**` ExponentiationExpression
     12 
     13  UpdateExpression :
     14    LeftHandSideExpression `++`
     15    LeftHandSideExpression `--`
     16    `++` UnaryExpression
     17    `--` UnaryExpression
     18 features: [exponentiation]
     19 ---*/
     20 
     21 var base = 4;
     22 assert.sameValue(--base ** 2, 9, "(--base ** 2) === 9");
     23 assert.sameValue(++base ** 2, 16, "(++base ** 2) === 16");
     24 assert.sameValue(base++ ** 2, 16, "(base++ ** 2) === 16");
     25 assert.sameValue(base-- ** 2, 25, "(base-- ** 2) === 25");
     26 
     27 base = 4;
     28 
     29 // --base ** --base ** 2 -> 3 ** 2 ** 2 -> 3 ** (2 ** 2) -> 81
     30 assert.sameValue(
     31  --base ** --base ** 2,
     32  Math.pow(3, Math.pow(2, 2)),
     33  "(--base ** --base ** 2) === Math.pow(3, Math.pow(2, 2))"
     34 );
     35 
     36 // ++base ** ++base ** 2 -> 3 ** 4 ** 2 -> 3 ** (4 ** 2) -> 43046721
     37 assert.sameValue(
     38  ++base ** ++base ** 2,
     39  Math.pow(3, Math.pow(4, 2)),
     40  "(++base ** ++base ** 2) === Math.pow(3, Math.pow(4, 2))"
     41 );
     42 
     43 base = 4;
     44 
     45 // base-- ** base-- ** 2 -> 4 ** 3 ** 2 -> 4 ** (3 ** 2) -> 262144
     46 assert.sameValue(
     47  base-- ** base-- ** 2,
     48  Math.pow(4, Math.pow(3, 2)),
     49  "(base-- ** base-- ** 2) === Math.pow(4, Math.pow(3, 2))"
     50 );
     51 
     52 // base++ ** base++ ** 2 -> 2 ** 3 ** 2 -> 2 ** (3 ** 2) -> 262144
     53 assert.sameValue(
     54  base++ ** base++ ** 2,
     55  Math.pow(2, Math.pow(3, 2)),
     56  "(base++ ** base++ ** 2) === Math.pow(2, Math.pow(3, 2))"
     57 );
     58 
     59 
     60 reportCompare(0, 0);