note

substring slice substr charAt includes startsWith endsWith repeat padStart padEnd

start index number からend index number(-1)までをnewStringとして返す。substringとsliceの違いは引数Endの値がMinusの時挙動が変わること ...
findnerd.com

substr() method in JavaScript String

JavaScript String substr() method : The substr() method is used to extract the sub-string from a string. It counts the index from 0. It returns the number of characters starts from the first parameter ...
GitHub

learn-slice-substring-substr

Description: From this lesson, we begin to learn about String objects. First of all, we have a look at the attributes of String: length. Use StringObject.length to ...