javascript - 计算内部二维数组的值 - javascript

Question

我有一个二维数组。我正在尝试计算内部数组中的值。我知道 JS array.length。但是执行 testData.length 会得到 5。这是准确的。但是，我想计算每个子数组中的项目数。

testData[0].length 会产生 6。但是我如何动态计算每个子数组？ (因为它会改变)。

var testData = [["column1","test1","test1","tea","party", "water bottle"],
                ["column2","test2","test2","test2 test2"],
                ["column3","test2","test2","test2 test2 "],
                ["column4","test2","test2 test2f asdfsdf"],
                ["column5","test2","test2 test2f asdfsdfasdfasdfasa asda asdfsas"]
]

Answer 1

使用reduce:

ES6:

const count = testData.reduce((currentCount, row) => currentCount + row.length, 0);

ES5:

var count = testData.reduce(function(currentCount, row) { 
    return currentCount + row.length;
}, 0);

文档:https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce