jquery.min.js?v=2.1.4:4 Uncaught TypeError: (b.contentType || "").indexOf is not a function

前台运行PUT时出现错误：jquery.min.js?v=2.1.4:4 Uncaught TypeError: (b.contentType || "").indexOf is not a function；

最后检查少了

原代码：

$.ajax({
    type: 'PUT',
    data: JSON.stringify(addData),
    contentType:"application/json",
    url: addr + "/information/update",
    contentType: function () {
        layerDialog = layer.msg('正在修改...',{
            icon: 16, shade:0.5
        });
        html = "";
    },

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改后代码：

type: 'PUT',
data: JSON.stringify(addData),
contentType:"application/json",
url: addr + "/information/update",
beforeSend: function () {
    layerDialog = layer.msg('正在修改...',{
        icon: 16, shade:0.5
    });
    html = "";
},

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