44 строки
1.3 KiB
JavaScript
44 строки
1.3 KiB
JavaScript
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/* Copyright 2016 Google Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License. */
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function onClick() {
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if (inputsAreEmpty()) {
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label.textContent = 'Error: one or both inputs are empty.';
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return;
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}
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updateLabel();
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}
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function inputsAreEmpty() {
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if (getNumber1() === '' || getNumber2() === '') {
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return true;
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} else {
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return false;
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}
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}
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function updateLabel() {
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var addend1 = getNumber1();
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var addend2 = getNumber2();
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var sum = addend1 + addend2;
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label.textContent = addend1 + ' + ' + addend2 + ' = ' + sum;
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}
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function getNumber1() {
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return inputs[0].value;
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}
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function getNumber2() {
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return inputs[1].value;
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}
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var inputs = document.querySelectorAll('input');
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var label = document.querySelector('p');
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var button = document.querySelector('button');
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button.addEventListener('click', onClick);
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