frankxuzy / js-calculator

js-calculator

Todo list:

• code refactor
• After click CE, cannot change operator.
• bug unsolved decimal calculations 0.2 + 0.1 = 0.30000000000000004

20 Feb

• Build html page.

21 Feb

• Add event listener. Print button innerHTML when clicked.
• Using .bind to on hold callback function.

22 Feb

• Mind map:

• Add printNum and printOperator function.
• Find a way to convert expression string into array

11+11*11/11 => [11, +, 11, *, 11, /, 11] 

• Add highPriorityOperatorIndex to check the index of first * or / if have.

23 Feb

• Add calcResults to handle the expression array and print result.

24 Feb

• Print the expression and result on page by click buttons.
• Add function to handle AC button.
• Fix bug when convert expression string to array.
• Add function if click number after click enter refresh the expression print.

25 Feb

New IDEA

    expressionStr = "";
    lastChar = expressionStr[expressionStr.length - 1];
    expressionArr = [];
- When click Num:
    check if it's dot. 
    expressionStr += num;
    lastChar = expressionStr[expressionStr.length - 1];

- When click operator:
    check if lastChar match operator 
        if not, push str into expressionArr. 
                push operator into expressionArr.
                empty expressionStr.
                lastChar = operator

It works! But code is ugly! need refactor.

26 Feb

• Add CE function
• Add keyboard num and operators input function
• Add minus button in html
• Add negative calc function
• Add function. When click operator after an operator, change to the current one.
• fix a bug when handle CE