ES6 used in everyday development is very common, in which the string processing capabilities strengthened, added several useful API, for example: trimStart, trimEnd, pasStart, padEnd, stratsWith, endsWith, include, repeat ... etc. Wait. Today we want to discuss is pasStart / pasEnd.
Once upon a time, when we deal with time formatting issues often encounter "fill zero problems", simply put, is under 100,000, a bit 0s, so there is the following code:
const seconds = str > 10 ? str : `0${str}`;
Such seems to be no problem, but since has ES6 happens, we have a more elegant wording, apply their knowledge, we can use ES6 new string API-padStart:
const seconds = str.padStart(2, "0");
Explain the parameters of usage padStar
The first parameter represents the maximum length of the string (containing string length string length before treatment + filled)
The second parameter indicates a string needs to be filled, if the parameter is not passed, the default fill spaces
Well, today share little skill you get it? Comments welcome exchange!