JSTests/test262/test/language/expressions/postfix-increment/S11.3.1_A3_T3.js

// Copyright 2009 the Sputnik authors.  All rights reserved.
// This code is governed by the BSD license found in the LICENSE file.

/*---
info: Operator x++ returns x = ToNumber(x) + 1
es5id: 11.3.1_A3_T3
description: Type(x) is string primitive or String object
---*/

//CHECK#1
var x = "1"; 
x++;
if (x !== 1 + 1) {
  throw new Test262Error('#1: var x = "1"; x++; x === 1 + 1. Actual: ' + (x));
}

//CHECK#2
var x = "x"; 
x++; 
if (isNaN(x) !== true) {
  throw new Test262Error('#2: var x = "x"; x++; x === Not-a-Number. Actual: ' + (x));
}

//CHECK#3
var x = new Number("-1"); 
x++; 
if (x !== -1 + 1) {
  throw new Test262Error('#3: var x = new String("-1"); x++; x === -1 + 1. Actual: ' + (x));
}