Google Earth engine (GEE) -- converts string to number and applies it to time search (ee.date.fromymd)

I wrote an article about how to convert strings into time , But there is no mention of applications , This time, , When we want to use the information provided in a string , When used for cutting , We can effectively convert strings to numeric types .

problem ：

Date (Error)

Number.int8, argument 'input': Invalid type. Expected type: Number. Actual type: String. Actual value: 1

  Original code ：

var string1 = ee.String('daymet_11_20150101');
print('26 firstring', string1);

var yearstr = ee.Number(string1.slice(10,14));
print('29 year', yearstr);

var monthstr = ee.Number(string1.slice(14,16));
print('32 month', monthstr);

var daystr = ee.Number(string1.slice(16,18));
print('35 day', daystr);

var hrstr = string1.slice(7,9);
print('38