Question

我在for循环中遇到问题，说它是重复的局部变量？我仍在尝试了解这一点，并已尽我所能调查并自行寻找答案，所以现在我向大家提问。如果您不介意，我想解释一下为什么它不起作用？

int x = 3;
String name = "Dirk";
x = x * 17;
System.out.print("x is " + x);
double d = Math.random();

while (x > 12) {
    x = x - 1;
}

for (int x = 0; x < 10; x = x + 1) {
    System.out.print("x is now " + x);
}

if (x == 10) {
    System.out.print("x must be 10");
} else {
    System.out.print("x isn't 10");
}
if ((x < 3) & (name.equals("Dirk"))) {
    System.out.println("Gently");
}

Answer 1

只需在module.exports = { entry: [ './src/index.js' ], output: { path: __dirname, publicPath: '/', filename: 'bundle.js' }, module: { rules: [ { exclude: /node_modules/, loader: 'babel-loader', query: { presets: ['react', ["es2015", { "modules": false }], 'stage-1'] } }, { test: /\.scss$/, use: [ "style-loader", // creates style nodes from JS strings "css-loader", // translates CSS into CommonJS "sass-loader" // compiles Sass to CSS ] } ] }, resolve: { extensions: ['.js', '.jsx', '.scss'] }, devServer: { historyApiFallback: true, contentBase: './', host: 'localhost', port: 8080 } };循环中删除x的第二个声明和重新分配：

for

否则，您可以简化以下说明：

for ( ; x < 10; x++) { System.out.print("x is now " + x); }而不是x++

x = x + 1而不是x*=19

复制局部变量x

1 个答案: