当我按下hp up按钮并超出技能点时如何阻止hp增大

Question

So i have a working function but its still going when i have 0 skill points http://prntscr.com/ns4tfx http://prntscr.com/ns4tld http://prntscr.com/ns4tse as you can see it keeps going up. it shouldn't do anything if skillpoints is at 0

I've tried messing around with if statements to fix it but no luck

Here's my Javascript code:

function HitPointsup(){
    if (SkillPoints>0 && rebirths >=1)  
        SkillPoints = SkillPoints - 1;
        HitPoints = HitPoints + 10;
        document.getElementById('SkillPoints').innerHTML = SkillPoints;
        document.getElementById("HitPoints").innerHTML = HitPoints;

Here's my html code:

 Skill Tree &nbsp; &nbsp; SP:<span id="SkillPoints1">0</span>
                <br />
                <br />
                <button id="HitPointsup" onclick="HitPointsup()">Hp 
up</button> &nbsp; <button id="SkillPoints2" onclick="Mp up()">Mp 
up</button>
                <br />
                <button id="SkillPoints3" onclick="Hp regen()">Hp 
regen</button>
                &nbsp;

I expect the hp up button to only work when i have skill points to spend ( i thought putting if(SkillPoints >0) would be enough). my acual results is you can keep pressing the button and hp keeps going up by 10. skill points stay at 0 tho no negative numbers there.

Answer 1

You are making a 'single line if', that means that only the first line below the if (SkillPoints>0 && rebirths >=1) is being verified. The other values are getting updated as-well. Try to user brackets like:

function HitPointsup(){
    if (SkillPoints>0 && rebirths >=1){  
        SkillPoints = SkillPoints - 1;
        HitPoints = HitPoints + 10;
    }
    document.getElementById('SkillPoints').innerHTML = SkillPoints;
    document.getElementById("HitPoints").innerHTML = HitPoints;
}