我使用 javascript 在 HTML 中创建了一个表格

Question

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Answer 1

The codepen helped immensely! I mentioned looking at the console output at one point. That's critically important because it's telling you what went wrong, so make sure you know how to see it . In codepen its at the bottom left as well, and there's a red exclamation mark in the JS showing that an error is present. When I hit the Metric button I see:

TypeError: obj.height is null

That's because some of your data has null for width or height instead of the value you're expecting, so it "crashes" and just stops at whatever row caused the problem. That's why some rows disappeared.

Two fixes I see:

• Fix your data so that the values don't have null in them
• Make the code more robust so it doesn't crash on invalid data (this is always preferable for any program).

For the second option, you can fix the code like this:

function MetricValues() { 
    var tab = document.querySelector("table");
    tab.innerHTML = "";
    for (var obj of death_row) {
        var height = obj.height || "0' 0\"";
        var row = `<tr><td>${obj.first_name}</td>
         <td>${obj.last_name}</td>
         <td>${obj.age_at_execution}</td>
         <td>${((obj.weight)/2.2046).toFixed(1)}</td>
         <td>${(((Number(height[0])*12*2.54) + (Number(height[3])*2.54))/100).toFixed(2)}</td></tr>`;
        tab.innerHTML += row;
    }
};

Using a temporary variable var height = obj.height || "0' 0\\""; var height = obj.height || "0' 0\\""; which defaults to 0' 0" fixes the crash. BTW you definitely should read up on functions .