How can I substitute any numeric value for argument in this.function.bind(this)
<pre><code>class hoge{
    constructor(key) {
        this.Idx = require("./myIndex.json");
    }
    foo(id, concepts){
        var aFunction = {
            "one": this.selectAction.bind(this),
            "two": this.selectAction.bind(this)
    }
    selectAction(id, concepts, number){
        return (id + concepts + this.Idx[number])

    }

}
</code></pre>

<p>How can I substitute any numerical value for only one argument of number in this.selectAction.bind(this) in aFunction method?
 For example, 
 "one": this.selectAction.bind(this, number = 0);
 "two": this.selectAction.bind(this, number = 1);</p>

<p>If I write like this, return this error
<code>
ReferenceError: number is not defined
</code></p>