html - how to fill input text on load?

I have an HTML form in the view and I need to fill out some input fields with json variables that come from the server. I don't want to write javascript code for each input field, instead, I want to access json variable in the value attribute of input tag.

I tested onload event for input tag but ot does not have any effects.

<input type="text" class="form-control" onload="this.value = 'value';" name="company[name]" />

Here is a pure/vanilla Javascript solution.

Keep the name of the <input> elements same as in the JSON data. The idea is to access the <input> with the keys from the JSON data.

Here is the working code snippet:

const values = {
  a: 5,
  b: 15
}

const keys = Object.keys(values)
const length = keys.length

for(let i = 0; i < length; i++){
    const key = keys[i]
    document.getElementsByName(key)[0].value = values[key]
}

<input type="text" class="form-control" name="a" />
<input type="text" class="form-control" name="b" />