Here's how to replace the word "dog" with the word "cat" in the given sentence in typescript:
const sentence: string = "the quick brown fox jumps over the lazy dog."; const replacedSentence: string = sentence.replace("dog", "cat"); console.log(replacedSentence); // "the quick brown fox jumps over the lazy cat."219 chars4 lines
replace() method is called on the sentence string with two arguments; the first argument is the string to be replaced ("dog"), and the second argument is the string to be substituted in its place ("cat"). The method returns a new string with the replacement made.