How can we enter an expression in c
Expression of what ? If its of characters, then you can use the gets() function to input.
for eg :
char input[size_of_expression]; // initialise a character array of required size to hold the expression gets(input); // inputs the expression
You can also use scanf() with “%s” as control string to read but the scanf() function stops reading after a blank space occurs in the expression. So if you have to input an expression like Hello world - it will read only Hello.