JS_Fundamentals/11_Functions.js at main · Christmith/JS_Fundamentals · GitHub

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"use strict"

/*-------------------function declaration---------------------------*/

let temperatures;
let sum;
let meanTemp;

function getMeanTemp() {
     sum = 0;
     for (let i = 0; i < temperatures.length; i++) {
         sum += temperatures[i];
     }
     meanTemp = sum / temperatures.length;
}

/*------------------calling function---------------------------*/

let temperatures;
let sum;
let meanTemp;

function getMeanTemp() {
     sum = 0;
     for (let i = 0; i < temperatures.length; i++) {
      sum += temperatures[i];
     }
     meanTemp = sum / temperatures.length;
}

temperatures = [12, 12, 11, 11, 10, 9, 9, 10, 12, 13, 15, 18, 21, 24, 24, 23, 25, 25, 23, 21, 20, 19, 17, 16];
getMeanTemp();
console.log(`mean: ${meanTemp}`); // -> mean: 16.666666666666668

temperatures = [17, 16, 14, 12, 10, 10, 10, 11, 13, 14, 15, 17, 22, 27, 29, 29, 27, 26, 24, 21, 19, 18, 17, 16];
getMeanTemp();
console.log(`mean: ${meanTemp}`); // -> mean: 18.083333333333332


/*-------------------------function local variables-----------------------------*/


let temperatures;
let meanTemp;

function getMeanTemp() {
     let sum = 0; //This is a local variable. We can use let or var keywords to declare local variables inside the function block
     for (let i = 0; i < temperatures.length; i++) {
       sum += temperatures[i];
     }
     meanTemp = sum / temperatures.length;
}

temperatures = [12, 12, 11, 11, 10, 9, 9, 10, 12, 13, 15, 18, 21, 24, 24, 23, 25, 25, 23, 21, 20, 19, 17, 16];
getMeanTemp();
console.log(`mean: ${meanTemp}`); // -> mean: 16.666666666666668

temperatures = [17, 16, 14, 12, 10, 10, 10, 11, 13, 14, 15, 17, 22, 27, 29, 29, 27, 26, 24, 21, 19, 18, 17, 16];
getMeanTemp();
console.log(`mean: ${meanTemp}`); // -> mean: 18.083333333333332


/*------------------------------return statements--------------------------------*/

let temperatures;
let meanTemp;

function getMeanTemp() {
     let sum = 0;
     let result;
     for (let i = 0; i < temperatures.length; i++) {
      sum += temperatures[i];
     }
     result = sum / temperatures.length;
     return result;
}

temperatures = [12, 12, 11, 11, 10, 9, 9, 10, 12, 13, 15, 18, 21, 24, 24, 23, 25, 25, 23, 21, 20, 19, 17, 16];
meanTemp = getMeanTemp();
console.log(`mean: ${meanTemp}`);

temperatures = [17, 16, 14, 12, 10, 10, 10, 11, 13, 14, 15, 17, 22, 27, 29, 29, 27, 26, 24, 21, 19, 18, 17, 16];
meanTemp = getMeanTemp();
console.log(`mean: ${meanTemp}`);


/*----------------------------Functions with parameters----------------------------*/

function getMeanTemp(temperatures) {
     let sum = 0;
     for (let i = 0; i < temperatures.length; i++) {
      sum += temperatures[i];
     }
     return sum / temperatures.length;
}

let day1 = [12, 12, 11, 11, 10, 9, 9, 10, 12, 13, 15, 18, 21, 24, 24, 23, 25, 25, 23, 21, 20, 19, 17, 16];
console.log(`mean: ${getMeanTemp(day1)}`); // -> mean:
16.666666666666668

let day2 = [17, 16, 14, 12, 10, 10, 10, 11, 13, 14, 15, 17, 22, 27, 29, 29, 27, 26, 24, 21, 19, 18, 17, 16];
console.log(`mean: ${getMeanTemp(day2)}`); // -> mean:
18.083333333333332

/*----------------------------Shadowing---------------------------------*/
let a = 100, b = 200, c = 300;

function test(a) {
     let b = 10;
     console.log(a); // parameter a
     console.log(b); // local variable b
     console.log(c); // global variable c
}

test(1);   // -> 1
      // -> 10
      // -> 300

console.log(a); // -> 100
console.log(b); // -> 200
console.log(c); // -> 300