| // Copyright (C) 2016 the V8 project authors. All rights reserved. |
| // This code is governed by the BSD license found in the LICENSE file. |
| /*--- |
| esid: sec-%typedarray%.prototype.lastindexof |
| description: returns index for the first found element |
| info: | |
| 22.2.3.17 %TypedArray%.prototype.lastIndexOf ( searchElement [ , fromIndex ] ) |
| |
| %TypedArray%.prototype.lastIndexOf is a distinct function that implements the |
| same algorithm as Array.prototype.lastIndexOf as defined in 22.1.3.15 except |
| that the this object's [[ArrayLength]] internal slot is accessed in place of |
| performing a [[Get]] of "length". |
| |
| 22.1.3.15 Array.prototype.lastIndexOf ( searchElement [ , fromIndex ] ) |
| |
| ... |
| 5. If n ≥ 0, then |
| a. If n is -0, let k be +0; else let k be min(n, len - 1). |
| 6. Else n < 0, |
| a. Let k be len + n. |
| 7. Repeat, while k ≥ 0 |
| a. Let kPresent be ? HasProperty(O, ! ToString(k)). |
| b. If kPresent is true, then |
| i. Let elementK be ? Get(O, ! ToString(k)). |
| ii. Let same be the result of performing Strict Equality Comparison |
| searchElement === elementK. |
| iii. If same is true, return k. |
| ... |
| includes: [testTypedArray.js] |
| features: [TypedArray] |
| ---*/ |
| |
| testWithTypedArrayConstructors(function(TA) { |
| var sample = new TA([42, 43, 42, 41]); |
| assert.sameValue(sample.lastIndexOf(42), 2, "lastIndexOf(42)"); |
| assert.sameValue(sample.lastIndexOf(43), 1, "lastIndexOf(43)"); |
| assert.sameValue(sample.lastIndexOf(41), 3, "lastIndexOf(41)"); |
| assert.sameValue(sample.lastIndexOf(41, 3), 3, "lastIndexOf(41, 3)"); |
| assert.sameValue(sample.lastIndexOf(41, 4), 3, "lastIndexOf(41, 4)"); |
| assert.sameValue(sample.lastIndexOf(43, 1), 1, "lastIndexOf(43, 1)"); |
| assert.sameValue(sample.lastIndexOf(43, 2), 1, "lastIndexOf(43, 2)"); |
| assert.sameValue(sample.lastIndexOf(43, 3), 1, "lastIndexOf(43, 3)"); |
| assert.sameValue(sample.lastIndexOf(43, 4), 1, "lastIndexOf(43, 4)"); |
| assert.sameValue(sample.lastIndexOf(42, 0), 0, "lastIndexOf(42, 0)"); |
| assert.sameValue(sample.lastIndexOf(42, 1), 0, "lastIndexOf(42, 1)"); |
| assert.sameValue(sample.lastIndexOf(42, 2), 2, "lastIndexOf(42, 2)"); |
| assert.sameValue(sample.lastIndexOf(42, 3), 2, "lastIndexOf(42, 3)"); |
| assert.sameValue(sample.lastIndexOf(42, 4), 2, "lastIndexOf(42, 4)"); |
| assert.sameValue(sample.lastIndexOf(42, -4), 0, "lastIndexOf(42, -4)"); |
| assert.sameValue(sample.lastIndexOf(42, -3), 0, "lastIndexOf(42, -3)"); |
| assert.sameValue(sample.lastIndexOf(42, -2), 2, "lastIndexOf(42, -2)"); |
| assert.sameValue(sample.lastIndexOf(42, -1), 2, "lastIndexOf(42, -1)"); |
| assert.sameValue(sample.lastIndexOf(43, -3), 1, "lastIndexOf(43, -3)"); |
| assert.sameValue(sample.lastIndexOf(43, -2), 1, "lastIndexOf(43, -2)"); |
| assert.sameValue(sample.lastIndexOf(43, -1), 1, "lastIndexOf(43, -1)"); |
| assert.sameValue(sample.lastIndexOf(41, -1), 3, "lastIndexOf(41, -1)"); |
| }); |