| Operators |
| Functions |
| Objects |
| Recursions |
==)== can be used to check whether two operands (i.e. values in a function) are equal, and Boolean results (i.e. True / False) will be produced.
Strings will be converted into numbers when compared with numbers.
===)=== compares two operands strictly, taking account of the different type of values, then produces Boolean results accordingly.
E.g. Strings are distinguished from numbers, hence "false" in results.
!=) and Strict Inequality (!==)Inequality operators compare whether two operands are distinguished (i.e. True) or not (i.e. False) by producing Boolean results.
Strict operators distinguish the types of operands as usual.
>) and Smaller than (<)>=) and Smaller than or equal (<=)&&)ALL criteria must be satisfied.
E.g. let x = 10; console.log(x > 8 && x < 15 && x < 11) will produce "True" results.
||)EITHER criteria must be satisfied.
E.g. let x = 10; console.log(x > 8 || x > 15 || x > 11) will still produce "True" results.
<html>
<body>
<p>First Example: <span id="demo1"></span></p>
<p>Second Example: <span id="demo2"></span></p>
<p>Third Example: <span id="demo3"></span></p>
<p>Chained if (Else-If) Example: <span id="demo4"></span></p>
<script>
let g = functionExample(2, 1, 3);
document.getElementById("demo1").innerHTML = g;
function functionExample(x, y, z) {
return (x + y) * z ;
}
</script>
<script>
let y = [2, 2];
let x = functionExample2(y[0], y[1]);
document.getElementById("demo2").innerHTML = x;
function functionExample2(a, b) {
if (a == b) {
return "Both values are equal or true because y = " + y;
}
return "Both values are not equal";
}
</script>
<script>
w = [2, "'2'"];
z = functionExample3(w[0], w[1]);
document.getElementById("demo3").innerHTML = z;
function functionExample3(a, b) {
if (a === b) {
return "Both values are equal or true because w = " + w;
} else {
return "Both values are NOT equal because w = " + w;
}
}
</script>
<script>
let num = 50;
document.getElementById("demo4").innerHTML = functionExample4(num);
function functionExample4(num) {
if (num > 70) {
return num + " is larger than 70";
} else if (num >= 60) {
return num + " is larger than or equal to 60";
} else {
return num + " is smaller than 60"
}
}
</script>
</body>
</html>
First Example:
Second Example:
Third Example:
Chained if (Else-If) Example:
const exampleObj = {
"property1": "eg1",
"property2": "eg2",
"property3": 3
};
console.log(exampleObj.property1);
//or
console.log(exampleObj["property2"]);
eg1
eg2
function displayNumbersFromTo(startNum, endNum) {
if(startNum > endNum) {
return [];
} else {
const display = displayNumbersFromTo(startNum + 1, endNum);
display.unshift(startNum);
return display;
}
};
console.log(displayNumbersFromTo(4, 20));
[ 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 ]
// If we replace .unshift() with .push(), the sequence will be reversed, i.e. [ 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4 ] .
//Detailed explanation at https://forum.freecodecamp.org/t/freecodecamp-challenge-guide-use-recursion-to-create-a-countdown/305925/2.