var quiz 85901000 creates an array var ex e x0 89 add the quiz grades quizTotal 0 for int i 0 i lt quizlength i quizTotal ID: 1028774
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1. Javascript Arrays
2. Array definition & for loopvar quiz = [85,90,100,0]; // creates an arrayvar ex = [];ex[0] = 89;// add the quiz gradesquizTotal = 0;for( int i=0; i< quiz.length; i++) quizTotal= quizTotal + quiz[i];quizTotal = quizTotal – quiz.min();
3. IndexingIndexing is the process of creating a sequence of names by associating a base name with a numberEach indexed item is called an element of the base-named sequenceAn index is enclosed in [square brackets] in JavaScript
4. Arrays [1]In programming, an indexed base name is called an arrayArrays must be declaredIn JavaScript, arrays are declared:var <variable> = new Array(<number of elements>)Notice that Array starts with an uppercase “A”
5. Arrays [2]Variables either are or are not arraysvar week = new Array(7);week is the identifier being declared,new Array(7) specifies that the identifier will be an array variable.number in parentheses gives the number of array elementsTo refer to an array’s length, we use <variable>.length
6. Arrays [3]Rules for arrays in JavaScript:Arrays are normal variables initialized by new Array(<number of elements>)<number of elements> in the declaration is just that—the number of array elementsArray indexing begins at 0Number of elements in an array is its lengthGreatest index of an array is <number of elements> − 1 (because the origin is 0)
7. Arrays [4]Array reference consists of array name with an index [enclosed in brackets] Value to which the index evaluates must be less than the array’s lengthExample:var dwarf = new Array(7); dwarf[0] = "Happy"; dwarf[1] = "Sleepy"; The number in the bracket is called the subscript
8. Conditional Operators>= greater than or equal to> Greater than< less than<= less than or equal to== equal to!= not equal to
9. If elsevar points= 87;if points >= 90 grade = “A”;else if points>=85 grade = “A-”
10. Function definitionWrite a function that generates two random numbers between 0-10 and adds them and returns them.function addTwo(){ var num1 = Math.random()*10; var num2 = Math.random()*10; var sum = num1 + num2; return sum;}
11. Function callA function has to be called in order to be activated.var total = addTwo();
12. One more functionWrite a function that rolls a pair of dice: if the sum > 10 return 1Else returns 0;
13. SummaryWe studiedIf ..elseFor .. LoopFunctionRandom function