!function (_stack) { var register; var variable = {}; for (let i = 0; i < _stack.length; i++) { instruct = _stack[i][0]; left = _stack[i][1]; right = _stack[i][2]; if (instruct === 110) { variable[right] = '' } if (instruct === 66) { if (right === '?') { variable[left] = register } else { variable[left] = right } } if (instruct === 88) { register = variable[left] + variable[right] } } ;console.log(variable) }([[110, 'var', 'a'], [66, 'a', 1000], [110, 'var', 'b'], [66, 'b', 1000], [110, 'var', 'c'], [66, 'c', 1000], [110, 'var', 'd'], [88, 'a', 'b'], [66, 'd', '?'], [110, 'var', 'e'], [88, 'd', 'c'], [66, 'e', '?']])