Checks if the given string contains whitespace.

(x: string) => boolean

containsWhitespace("test string");
// ⇒ true

containsWhitespace("test");
// ⇒ false

• How to check if a string contains whitespace?

Empty string.

""

empty();
// ⇒ ""

• How to get an empty string?

Transforms the first character to lowercase.

(text: string) => string

firstToLower("TeSt");
// ⇒ "teSt"

• How to make the first letter of a string lowercase?

Transforms the first character to uppercase.

(text: string) => string

firstToUpper("teSt");
// ⇒ "TeSt"

• How to make the first letter of a string uppercase?

Checks if the given substring is present in the source string.

(search: string) => (text: string) => boolean

includes("brown fox")("The quick brown fox jumps over the lazy dog");
// ⇒ true

includes("brown dog")("The quick brown fox jumps over the lazy dog");
// ⇒ false

• How to check if a string contains a given substring?

Non-breaking space.

" "

nbsp;
// ⇒ " "

• How to get a non-breaking space?

Checks if the given string is present and is not empty or all whitespace.

(x?: string) => boolean

nonEmpty("test with spaces");
// ⇒ true

nonEmpty("   ");
// ⇒ false

nonEmpty(null);
// ⇒ false

• How to check if a string is non-empty?
• How to check if a string is not all whitespace?
• How to check if a string is not null or undefined?

Checks if the given string starts with the given substring.

(prefix: string) => (xs: string) => boolean

startsWith("The")("The quick brown fox jumps over the lazy dog");
// ⇒ true

startsWith("Quick")("The quick brown fox jumps over the lazy dog");
// ⇒ false

• How to check if a string starts with a given substring?