Question

我需要基本上重复以下内容，直到a10和g10。所以我理论上可以继续如下，并最终有大量的重复，但我知道这是一个可怕的做法。简化这一点的最佳方法是什么？

function enterall() {


    var a1 =    localStorage.getItem('a1');
    var b1 =    localStorage.getItem('b1');
    var c1 =    localStorage.getItem('c1');
    var d1 =    localStorage.getItem('d1');
    var e1 =    localStorage.getItem('e1');
    var f1 =    localStorage.getItem('f1');
    var g1 =    localStorage.getItem('g1');

    var a2 =    localStorage.getItem('a2');
    var b2 =    localStorage.getItem('b2');
    var c2 =    localStorage.getItem('c2');
    var d2 =    localStorage.getItem('d2');
    var e2 =    localStorage.getItem('e2');
    var f2 =    localStorage.getItem('f2');
    var g2 =    localStorage.getItem('g2');



db.transaction(function (tx) {

               tx.executeSql("INSERT INTO mytable (id, item, code, val, val2, val3, val4) VALUES (?,?,?,?,?,?,?)", [a1, b1, c1, d1, e1, f1, g1], function (tx, results){

                             alert('records in');

                             });
              });


db.transaction(function (tx) {

               tx.executeSql("INSERT INTO mytable (id, item, code, val, val2, val3, val4) VALUES (?,?,?,?,?,?,?)", [a2, b2, c2, d2, e2, f2, g2], function (tx, results){

                             alert('records in');

                             });
              });
};

Answer 1

您应该使用嵌套for循环和数组来包含您的值：

var values = new Object();
var letters = ["a", "b", "c", "d", "e", "f", "g"];

letters.forEach(function(letter) {
    for (var i = 1; i <= 10; i++) {
        values[letter + i] = localStorage.getItem(letter + i);
    }
});

Answer 2

尝试这样的事情：

var results = {'first': [], 'second': []};
var letters = ['a', 'b', 'c', 'd', 'e', 'f', 'g'];

for (var i = 0; i < 7; i++) {
    results['first'].push(localStorage.getItem(letters[i] + '1'));
    results['second'].push(localStorage.getItem(letters[i] + '2'));
}

Answer 3

除了先前的答案，我还建议为db.transaction函数使用循环。作为单独的函数，这两个函数都会更好，从enterall（）函数中调用。我想要的另一个建议就是将它们变成对象，既可以添加到localStorage，也可以将它们取出来，以使代码更清晰。

Answer 4

如果您不想创建阵列，也可以使用它：

for(var num=1; num <= 10; num++) {
    var arr = [];
    for(var letter = 'a'.charCodeAt(0); letter <= 'g'.charCodeAt(0); letter ++) {
        arr.push(localStorage.getItem(String.fromCharCode(letter) + num));
    }
    db.transaction(function (tx) {
        tx.executeSql("INSERT INTO mytable (id, item, code, val, val2, val3, val4) VALUES (?,?,?,?,?,?,?)", arr, function (tx, results){
            alert('records in');
        });
    });
}

正确实现for循环

4 个答案: