前端如何判空

        这样判空就会报错 

                loadNode(node, resolve)console.log("node")console.log(node)if (node.data !== null) {this.get(ctx + '/publicity/publicityType/typeTreeData?id=' + node.data.id).then((res) => {resolve(res)})}},

        需要这样写，用typeof来做类型判断

                console.log("node")console.log(node)if (typeof node.data !== 'undefined') {this.get(ctx + '/publicity/publicityType/typeTreeData?id='+node.data.id).then((res) => {resolve(res)})}else {this.get(ctx + '/publicity/publicityType/typeTreeData?id='+this.typeId).then((res) => {resolve(res)})}