Question

我正在使用replace方法替换一些文本，例如： -

let data = "My name is [[employeeName]]";

data.replace('[[employeeName]]', this.employee.employeeName);

现在我关注的是员工object，null，如果是null，那么上面的代码就会失败。所以我想把条件设置成这样的东西：

{this.employee ? this.employee.employeeName : ''}

如何在replace()方法中添加条件？

请帮助我

Answer 1

使用

(this.employee && this.employee.employeeName) || "";

即

data.replace('[[employeeName]]', (this.employee && this.employee.employeeName) || "" );

注意

当[[employeeName]]和""中的任何一个this.employee时，这会将this.employee.employeeName替换为undefined。

即，如果您的对象是

var obj = {}; data.replace('[[employeeName]]', (obj.employee && obj.employee.employeeName) || "" ); //will still replace [[employeeName]] with ""

和

var obj = { employee : {} }; data.replace('[[employeeName]]', (obj.employee && obj.employee.employeeName) || "" ); //will still replace [[employeeName]] with ""

但如果employeeName存在

var obj = { employee : { employeeName : "emp" } }; data.replace('[[employeeName]]', (obj.employee && obj.employee.employeeName) || "" ); //will replace [[employeeName]] with "emp"

Answer 2

最简单的方法是添加一个'OR'评估，并检查员工对象也不为空：

data.replace('[[employeeName]]', this.employee ? this.employee.employeeName || "" : "");

如果employee为null，或者employee name为null，则将替换为空字符串。

Answer 3

如果你真的想使用三元表达式：

let name = this.employee? this.employee.employee.name: '';
let data = "My name is [[employeeName]]";
data.replace('[[employeeName]]', name);

或者只是将你的代码放在if else语句中：

如果你这样做，你实际上并不需要替换功能：

if(!(typeof employee ==="undefined")){
       let data= "My name is "+ this.employee.employeeName;
    }
    else{
      let data = "My name is nobody";
    }

我们如何在string.replace方法中检查null？

3 个答案: