JavaScript: Check whether a given string represents a correct sentence or not

JavaScript Basic: Exercise-114 with Solution

Check String as Correct Sentence

Write a JavaScript program to check whether a given string represents a correct sentence or not. A string is considered a correct sentence if it starts with a capital letter and ends with a full stop (.).

Sample Solution:

JavaScript Code:

// Check if the input string is a correct sentence based on certain conditions
function is_correct_Sentence(input_str) {
    var first_char = input_str[0]; // Get the first character of the string
    var last_char = input_str[input_str.length - 1]; // Get the last character of the string
    return /[A-Z]/.test(first_char) && last_char == "."; // Check if the first character is an uppercase letter and the last character is a period.
}

// Examples of checking correct sentences using the function
console.log(is_correct_Sentence("This tool will help you write better English and efficiently corrects texts.")); // Output: true (It's a correct sentence)
console.log(is_correct_Sentence("This tool will help you write better English and efficiently corrects texts")); // Output: false (Missing period at the end)
console.log(is_correct_Sentence("this tool will help you write better English and efficiently corrects texts.")); // Output: false (First letter should be capitalized)

Output:

true
false
false

Live Demo:

See the Pen javascript-basic-exercise-114 by w3resource (@w3resource) on CodePen.

Flowchart:

ES6 Version:

// Check if the input string is a correct sentence based on certain conditions
const is_correct_Sentence = (input_str) => {
    // Get the first character of the string
    const first_char = input_str[0];
    // Get the last character of the string
    const last_char = input_str[input_str.length - 1];
    // Check if the first character is an uppercase letter and the last character is a period
    return /[A-Z]/.test(first_char) && last_char === ".";
};

// Examples of checking correct sentences using the function
console.log(is_correct_Sentence("This tool will help you write better English and efficiently corrects texts.")); // Output: true (It's a correct sentence)
console.log(is_correct_Sentence("This tool will help you write better English and efficiently corrects texts")); // Output: false (Missing period at the end)
console.log(is_correct_Sentence("this tool will help you write better English and efficiently corrects texts.")); // Output: false (First letter should be capitalized)

For more Practice: Solve these Related Problems:

• Write a JavaScript program that checks if a string starts with an uppercase letter and ends with a period after trimming whitespace.
• Write a JavaScript function that validates sentence structure by ensuring proper capitalization and punctuation.
• Write a JavaScript program that verifies whether a given string qualifies as a correct sentence based on initial capital and ending full stop criteria.

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