我们都知道全局变量不是最佳实践.但有几个例子,没有它们很难编码.您使用什么技术来避免使用全局变量?
例如,给定以下场景,您将如何使用全局变量?
JavaScript代码:
var uploadCount = 0;
window.onload = function() {
var frm = document.forms[0];
frm.target = "postMe";
frm.onsubmit = function() {
startUpload();
return false;
}
}
function startUpload() {
var fil = document.getElementById("FileUpload" + uploadCount);
if (!fil || fil.value.length == 0) {
alert("Finished!");
document.forms[0].reset();
return;
}
disableAllFileInputs();
fil.disabled = false;
alert("Uploading file " + uploadCount);
document.forms[0].submit();
}
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相关标记:
<iframe src="test.htm" name="postHere" id="postHere"
onload="uploadCount++; if(uploadCount > 1) startUpload();"></iframe>
<!-- MUST use inline JavaScript here for onload event
to …Run Code Online (Sandbox Code Playgroud) 你有没有在javascript中合并两个jsons?
问题:
a={id:123,name:john,status:success};
b={id:123,status:inprocess,transId:245};
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输出json应该是这样的
{id:123,name:john,status:success,transId:245};
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a中的所有值都应覆盖b中的值,并且不常见的键/值应出现在输出json中.
我尝试了一些递归选项,但是cudnt实现了输出.