Statements
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Expert Answer & Key Takeaways
Mastering Statements is essential for high-fidelity technical architecture and senior engineering roles in 2026.
JavaScript Statements
A computer program is a list of "instructions" to be "executed" by a computer. In a programming language, these programming instructions are called statements. A JavaScript program is a list of programming statements.
1. Structure of a Statement
JavaScript statements are composed of: Values, Operators, Expressions, Keywords, and Comments.
let x, y, z; // Statement 1: Declare variables
x = 5; // Statement 2: Assign value
y = 6; // Statement 3: Assign value
z = x + y; // Statement 4: Compute z2. Semicolons (;)
Semicolons separate JavaScript statements. In 2026, while many modern environments handle Automatic Semicolon Insertion (ASI), adding semicolons at the end of each executable statement is a Best Practice for professional engineering.
let a, b, c;
a = 5;
b = 6;
c = a + b;3. Whitespace & Line Length
JavaScript ignores multiple spaces. You can add white space to your script to make it more readable.
let person = "Hege";
let person="Hege"; // Both are valid, but the first is more readableFor best readability, programmers often like to avoid code lines longer than 80 characters. If a JavaScript statement does not fit on one line, the best place to break it is after an operator.
document.getElementById("demo").innerHTML =
"Hello Dolly!";4. JavaScript Code Blocks
JavaScript statements can be grouped together in code blocks, inside curly brackets
{...}. The purpose of code blocks is to define statements to be executed together. The most common place to find statements grouped in blocks is in functions.function myFunction() {
document.getElementById("demo1").innerHTML = "Hello Dolly!";
document.getElementById("demo2").innerHTML = "How are you?";
}5. JavaScript Keywords
JavaScript statements often start with a keyword to identify the JavaScript action to be performed.
| Keyword | Description |
|---|---|
break | Terminates a switch or a loop |
continue | Jumps out of a loop and starts at the top |
debugger | Stops the execution of JavaScript, and calls the debugging function |
do ... while | Executes a block of statements, and repeats the block, while a condition is true |
for | Marks a block of statements to be executed, as long as a condition is true |
function | Declares a function |
if ... else | Marks a block of statements to be executed, depending on a condition |
return | Exits a function |
switch | Marks a block of statements to be executed, depending on different cases |
try ... catch | Implements error handling to a block of statements |
var / let / const | Declares a variable |
Top Interview Questions
?Interview Question
Q:Why are semicolons used in JavaScript?
A:
Semicolons are used to separate JavaScript statements. While sometimes optional due to automatic insertion, explicitly using them ensures code clarity and prevents subtle bugs especially when minifying code.
?Interview Question
Q:What is a JavaScript code block?
A:
A code block is a group of JavaScript statements enclosed in curly brackets {...}. They are used to group statements that should be executed together, most commonly seen in function definitions and loops.
?Interview Question
Q:How should you break a long JavaScript statement for readability?
A:
If a statement is too long for one line, it is best practice to break it after an operator (like = or +) to maintain clear intent.
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