set default value for inputfield with script

Questions & Answers
1

so theres an inputfield, you put in number hit calculate button, number goes through some equation and shows answer. when I dont put in any number and hit calculate, it shows error,
but I want something like, when you dont enter any value, it assumes the value to be zero, like so

    if (InputField.text == null)
    {
        text  = 0;
    }

what I dont want is enter zero in Text here because it will overright place holder, which says enter value here, so placeholder is necessary. please help. thank you.

2

public void OnInputFieldValidated()
{
if( !string.isNullOrEmpty( inputField.text ) )
{
inputField.text = parseExpression( inputField.text ).ToString() ; // Supposing you have such function to parse an compute the result of the input field
}
else
{
inputField.text = 0.ToString();
}
}