I have a string "str1+str2-str3*str4".  
I want to split it so I get an array
['str1','+','str2','-','str3','*','str4'].  
Could someone help provide a solution?
I have a string "str1+str2-str3*str4".  
I want to split it so I get an array
['str1','+','str2','-','str3','*','str4'].  
Could someone help provide a solution?