This content originally appeared on Go Make Things and was authored by Go Make Things
JavaScript provides a bunch of methods for adding and removing leading and trailing characters from strings. Today, we’re going to look a bunch of them.
Let’s dig in!
The String.padStart() method
The String.padStart() method adds characters to the beginning of a string if it’s less than a certain length. This is particularly useful for numbers that need leading 0’s (but can do so much more than that).
The String.padStart() method accepts two arguments: the length the string should be, and what characters to add if it’s not that length. The characters to use is option, and defaults to a space ().
// Add a leading zero for hours below 10
let hour3 = '3';
let hour12 = '12';
// returns "03"
hour3.padStart(2, '0');
// returns "12"
hour12.padStart(2, '0');
The String.padEnd() method
The String.padEnd() method adds characters to the end of a string if it’s less than a certain length. This is particularly useful for numbers that need trailing 0’s.
The String.padEnd() method accepts two arguments: the length the string should be, and what characters to add if it’s not that length. The characters to use is option, and defaults to a space ().
// Add a leading zero for hours below 10
let minutes0 = '0';
let minutes12 = '12';
// returns "00"
minutes0.padEnd(2, '0');
// returns "12"
minutes12.padEnd(2, '0');
The String.trim() method
The String.trim() method removes leading and trailing whitespace from a string.
let str = ' I love Cape Cod potato chips. ';
// Returns "I love Cape Cod potato chips."
str.trim();
String concatenation
You can use string concatenation to combine two or more strings together. Combine strings using the addition operator (+).
/**
* Strings as variables
*/
let str1 = 'I love Cape Cod potato chips.';
let str2 = 'What about you?';
let concat = str1 + ' ' + str2;
// logs "I love Cape Cod potato chips. What about you?"
console.log(concat);
/**
* Creating a new variable from two strings
*/
let concat2 =
'I love Cape Cod potato chips. ' +
'What about you?';
// logs "I love Cape Cod potato chips. What about you?"
console.log(concat2);
This content originally appeared on Go Make Things and was authored by Go Make Things
Go Make Things | Sciencx (2022-01-21T15:30:00+00:00) The many ways to modify leading and trailing characters from strings with JavaScript. Retrieved from https://www.scien.cx/2022/01/21/the-many-ways-to-modify-leading-and-trailing-characters-from-strings-with-javascript/
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