Part 2
In part 2 of this series, we look at creating UUIDs, how to reverse all the characters in a string, and how to capitalize the first letter of a string parameter.
Snippet 4 - Create UUID for the browser
To create a UUID (Universally Unique Identifier
) we make use of the built-in Node-module crypto. The function beneath will create a UUID that is compliant with RFC4122
.
function createUUIDInBrowser() {
return ([1e7] + -1e3 + -4e3 + -8e3 + -1e11).replace(/[018]/g, (c) =>
(c ^ (crypto.getRandomValues(new Uint8Array(1))[0] & (15 >> (c / 4)))).toString(16)
);
}
Snippet 5 - Reverse the characters in a string
The next snippet is reversing all the characters that are passed in the str
parameter. A parameter value of Dev.to
will return ot.veD
after calling the function.
function reverseString(str) {
return [...str].reverse().join("");
}
Snippet 6 - Capitalize the first letter of a string
The following Javascript snippet will return the input string with the first character capitalized. You can pass a second variable to the function lowerCaseRestOfString
, but this is not required (variable is default false)
The secondary variable will lowercase the rest of the the inputted string
function capitalizeFirstLetterOfString([firstChar, ...restOfChars], lowerCaseRestOfString = false) {
return first.toUpperCase() + (lowerRest ? rest.join("").toLowerCase() : rest.join(""));
}
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