Gil Barbara
50 lines
1.2 KiB
JavaScript
50 lines
1.2 KiB
JavaScript
module.exports = {
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expr (expr) {
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var chars = expr.split('');
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var n = [], op = [], index = 0, oplast = true;
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n[index] = '';
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// Parse the expression
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for (var c = 0; c < chars.length; c++) {
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if (isNaN(parseInt(chars[c], 10)) && chars[c] !== '.' && !oplast) {
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op[index] = chars[c];
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index++;
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n[index] = '';
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oplast = true;
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}
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else {
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n[index] += chars[c];
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oplast = false;
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}
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}
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// Calculate the expression
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expr = parseFloat(n[0]);
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for (var o = 0; o < op.length; o++) {
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var num = parseFloat(n[o + 1]);
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switch (op[o]) {
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case '+':
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expr = expr + num;
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break;
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case '-':
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expr = expr - num;
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break;
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case '*':
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expr = expr * num;
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break;
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case '/':
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expr = expr / num;
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break;
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default:
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break;
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}
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}
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return expr;
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}
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};
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