33 lines
1.1 KiB
C++
33 lines
1.1 KiB
C++
// choices.cpp -- array variations
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#include <iostream>
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#include <vector> // STL C++98
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#include <array> // C++0x
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int main()
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{
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using namespace std;
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// C, original C++
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double a1[4] = {1.2, 2.4, 3.6, 4.8};
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// C++98 STL
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vector<double> a2(4); // create vector with 4 elements
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// no simple way to initialize in C98
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a2[0] = 1.0/3.0;
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a2[1] = 1.0/5.0;
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a2[2] = 1.0/7.0;
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a2[3] = 1.0/9.0;
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// C++0x -- create and initialize array object
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array<double, 4> a3 = {3.14, 2.72, 1.62, 1.41};
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array<double, 4> a4;
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a4 = a3; // valid for array objects of same size
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// use array notation
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cout << "a1[2]: " << a1[2] << " at " << &a1[2] << endl;
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cout << "a2[2]: " << a2[2] << " at " << &a2[2] << endl;
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cout << "a3[2]: " << a3[2] << " at " << &a3[2] << endl;
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cout << "a4[2]: " << a4[2] << " at " << &a4[2] << endl;
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// misdeed
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a1[-2] = 20.2;
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cout << "a1[-2]: " << a1[-2] <<" at " << &a1[-2] << endl;
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cout << "a3[2]: " << a3[2] << " at " << &a3[2] << endl;
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cout << "a4[2]: " << a4[2] << " at " << &a4[2] << endl;
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// cin.get();
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return 0;
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} |